Back to results
US 5,014,863 AGranted
Vehicle mounted crane
AssigneeIowa Mold Tooling Co., Inc.
InventorJames Vlaanderen
Life of this patent
Estimating the term…
Abstract
The possibility of the end 26 of a boom 20 of a vehicle mounted crane being moved downwardly into engagement with part of the crane or the vehicle on which it is mounted and causing damage thereto during elevation of a mast 18 for the crane from a stowed position (FIG. 2) to an elevated position (FIG. 1) is avoided in a construction wherein the mast 18 is formed of a parallelogram linkage including rigid links 60 and cylinders 72 which assure that the attitude of the boom 20 relative to a base 10 for the crane will not change during elevation of the mast 18.
Claims13
A crane construction comprising:
- a base;
- outriggers secured to said base and having vertically movable, ground engaging pads adapted to steady said base in relation to the underlying terrain;
- a boom located above said base and including first and second, opposed ends;
- load lifting means on said boom at said first end;
- and
- a collapsible mast interconnecting said boom second end and said base, said mast including a rigid link pivoted at a first pivot to said base and at a second, spaced pivot to said boom, a first extensible cylinder having a rod generally parallel to said link pivoted at a third pivot to said base and a fourth, spaced pivot to said boom and operable to raise or lower said boom on said mast, the distance between said first and third pivots, and said second and fourth pivots being substantially equal, said first cylinder being configurable to have a length substantially equal to the length of said rigid link to define a parallelogram linkage, and a second extensible cylinder extending diagonally between and pivotally connected to opposite corners of said parallelogram linkage;
- whereby said mast may be collapsed or extended on said base by operation of said second cylinder and without changing the attitude of said boom relative to said base.
4 more elements
A crane construction adapted for mounting on a vehicle comprising:
- a base;
- a boom located above said base and including first and second, opposed ends;
- load lifting means on said boom at said first end;
- and
- a collapsible mast interconnecting said boom second end and said base, said mast including a rigid link pivoted at a first pivot to said base and at a second spaced pivot to said boom, a variable length link generally parallel to said rigid link and pivoted at a third pivot to said base and a fourth spaced pivot to said boom and operable to raise or lower said boom on said mast, the distance between said first and third pivots, and said second and fourth pivots being substantially equal, said variable length link being configurable to have a length substantially equal to the length of said rigid link to define a parallelogram linkage and an extensible cylinder extending diagonally between and pivotally connected to opposite corners of said parallelogram linkage;
- whereby said mast may be collapsed or extended on said base by operation of said cylinder and without changing the attitude of said boom relative to said base.
3 more elements
A vehicle mounted crane construction comprising:
- a base adapted to be mounted on a vehicle;
- a boom located above said base and including first and second, opposed ends;
- load lifting means on said boom at said first end;
- and
- a collapsible mast interconnecting said boom second end and said base, said mast including a rigid link pivoted at a first pivot to said base and at a second spaced pivot to said boom, a variable length link generally parallel to said rigid link and pivoted at a third pivot to said base and a fourth, spaced pivot to said boom and operable to raise or lower said boom on said mast, the distance between said first and third pivots, and said second and fourth pivots being substantially equal, said variable length link being configurable to have a length substantially equal to the length of said rigid link to define a parallelogram linkage and a motor for changing the distance between opposite corners of said parallelogram linkage;
- whereby said mast may be collapsed or extended on said base by operation of said motor and without changing the attitude of said boom relative to said base.
3 more elements
Dependencies are inferred from the claim text.