US3910440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertical lift, extendible reach mechanism for a truck
Assignee: Doosan Bobcat North America Inc
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Filing: 1973-07-11
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Granted: 1975-10-07
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Expires: 1993-07-11
Abstract
Abstract A vertical lift extendible reach mechanism for a truck having a forward end and a rearward end in which one or more posts are mounted on the rear of the truck and a boom is pivotally connected to the upper end of the post and extends forwardly over the truck and supports an attachment on the forward end. A power means pivots the post forwardly and rearwardly to move the boom and attachment forwardly and rearwardly, and a power means raises and lowers the forward end of the boom. A third power means, such as a hydraulic cylinder, controls the forward end of the boom and the attachment thereon, as the second mentioned power means is operated, to cause the forward end of the boom and the attachment to move in a substantially vertical line between its lowered and raised positions. The hydraulic cylinder for controlling the forward end of the boom may operate telescopic sections in the boom to retract and extend as the forward end thereof is moved between its two positions.
Inventors
- 👤 Donald A Holtkamp
- 👤 Willard L Chichester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:59
CPC Classifications
B; B66; B66F; B66F9/00; B66F9/06; B66F9/065; B66F9/0655
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
223 words
A vertical lift, extendible reach mechanism for a truck having a forward end and a rearward end, comprising a post pivotally connected at its lower end to the rear of the truck, a boom pivotally connected to the upper end of said post and extending forwardly therefrom, said boom having telescopic sections for varying the effective length thereof, a load carrying attachment connected to the forward end of said boom, a power means connected to said post for pivoting said post forwardly and rearwardly to move said boom and load attachment forwardly and rearwardly, a power means for lifting and lowering the forward end of the boom while pivoting on said post, a hydraulic cylinder moving said telescopic sections relative to one anotehr for retracting the forward end of the boom as said end is raised to a point substantially level with the rear pivot point of said boom and for extending the forward end of the boom as said end is raised above said pivot point to cause said forward end and attachment thereon to move iN a substantially straight vertical line between their lowered and raised positions, a hydraulic system having a control valve means therein for operating said cylinder, and a switch means responsive to the movement of said telescopic sections actuating said valve means to extend said telescopic section.
Claim 2
Dependent Claim
223 words
A vertical lift, extendible reach mechanism for a truck having a forward end and a rearward end, comprising a post pivotally connected at its lower end to the rear of the truck, a boom pivotally connected to the upper end of said post and extending forwardly therefrom, said boom having telescopic sections for varying the effective length thereof, a load carrying attachment connected to the forward end of said boom, a power means connected to said post for pivoting said post forwardly and rearwardly to move said boom and load attachment forwardly and rearwardly, a power means for lifting and lowering the forward end of the boom while pivoting on said post, a hydraulic cylinder moving said telescopic sections relative to one anotehr for retracting the forward end of the boom as said end is raised to a point substantially level with the rear pivot point of said boom and for extending the forward end of the boom as said end is raised above said pivot point to cause said forward end and attachment thereon to move iN a substantially straight vertical line between their lowered and raised positions, a hydraulic system having a control valve means therein for operating said cylinder, and a switch means responsive to the movement of said telescopic sections actuating said valve means to extend said telescopic section.
Claim 3
Dependent Claim
32 words
A vertical lift, extendible reach mechanism for a truck as defined in claim 1, in which said power means for retracting and extending said boom consists of a double acting hydraulic cylinder.
Claim 4
Dependent Claim
59 words
A vertical lift, extendible reach mechanism for a trucak as defined in claim 1, in which said hydraulic cylinder is operated simultaneously with the operation of said second power means to maintain the forward end of the boom and the attachment therein on a substantially vertical line as the boom is raised and lowered by said second power means.
Claim 5
Dependent Claim
58 words
A vertical lift, extendible reach mechanism for a truck as defined in claim 2, in which said hydraulic cylinder is operated simultaneously with the operation of said second power means to maintain the forward end of the boom and the attachment therein on a substantially vertical line as the boom is raised and lowered by said power means.
Claim 6
Dependent Claim
148 words
In a vertical lift, extendible reach mechanism for a truck having a forward end and a rearward end, a post pivotally connected at its lower end to the rear end of the truck, and a boom pivotally connected to the upper end of said post and extending forwardly therefrom: a system including telescopic sections in the boom for retracting and extending the forward end of the boom as the forward end of the boom is moved from its lowered to its elevated position, and power means included in said boom for moving said telescopic sections relative to one another, and a control means responsive to the raising and lowering movement of the forward end of said boom for operating said power means to move said telescopic sections relative to one another to cause said forward end to follow a substantially vertical path as it is raised and lowered.
Claim 7
Dependent Claim
148 words
In a vertical lift, extendible reach mechanism for a truck having a forward end and a rearward end, a post pivotally connected at its lower end to the rear end of the truck, and a boom pivotally connected to the upper end of said post and extending forwardly therefrom: a system including telescopic sections in the boom for retracting and extending the forward end of the boom as the forward end of the boom is moved from its lowered to its elevated position, and power means included in said boom for moving said telescopic sections relative to one another, and a control means responsive to the raising and lowering movement of the forward end of said boom for operating said power means to move said telescopic sections relative to one another to cause said forward end to follow a substantially vertical path as it is raised and lowered.
Claim 8
Independent Claim
42 words
A system as defined in calim 5 in which a power means raises and lowers the forward end of said boom and means is provided for simultaneously operating said telescopic sections and the power means as the boom is raised and lowered.
Claim 9
Independent Claim
42 words
A system as defined in calim 5 in which a power means raises and lowers the forward end of said boom and means is provided for simultaneously operating said telescopic sections and the power means as the boom is raised and lowered.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |