Load condition indicating method and apparatus for forklift truck
First Claim
1. A method of indicating a load condition of a forklift truck having a tilt mechanism for tilting a mast and a lift mechanism for lifting a fork along said mast, comprising the steps of:
- detecting loads applied to said tilt and lift mechanisms while a cargo is placed on said fork;
calculating a weight of said cargo and a centroid position of the same based on the detected loads applied to said tilt and lift mechanisms; and
displaying the load condition by indicating the calculated cargo weight and centroid position at least by a point which is located in a coordinate system having at least two axes one of which represents the calculated cargo weight as a first variable and the other of which represents the calculated centroid position as a second variable, said coordinate system providing a border line indicating an overload criterion area determined based on a forecast of overturn of said forklift truck.
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Accused Products
Abstract
An indicating method and apparatus of cargo load condition of a forklift truck. In this method and apparatus weight and centroid position of the loaded cargo are calculated by a calculation control circuit based on loads applied to a lift mechanism and a tilt mechanism of the truck. The calculated weight and centroid position are displayed on two-dimensional coordinates illustrated on a displaying device in contrast with an overturn danger line which is determined forecasting the forward overturn of the truck. The load condition may be displayed in three-dimensional coordinates in relation to lift height of the cargo as well as the weight and the centroid position thereof.
148 Citations
9 Claims
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1. A method of indicating a load condition of a forklift truck having a tilt mechanism for tilting a mast and a lift mechanism for lifting a fork along said mast, comprising the steps of:
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detecting loads applied to said tilt and lift mechanisms while a cargo is placed on said fork; calculating a weight of said cargo and a centroid position of the same based on the detected loads applied to said tilt and lift mechanisms; and displaying the load condition by indicating the calculated cargo weight and centroid position at least by a point which is located in a coordinate system having at least two axes one of which represents the calculated cargo weight as a first variable and the other of which represents the calculated centroid position as a second variable, said coordinate system providing a border line indicating an overload criterion area determined based on a forecast of overturn of said forklift truck. - View Dependent Claims (2)
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3. An apparatus for indicating a load condition of a forklift truck having a tilt cylinder for tilting a mast and a lift cylinder for lifting a fork along said mast, comprising:
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a lift pressure sensor detecting a first hydraulic pressure developed in said lift cylinder while a cargo is placed on said fork, said lift pressure sensor producing a lift pressure signal; a tilt pressure sensor detecting a second hydraulic pressure in said tilt cylinder during the placement of said cargo on said fork and producing a tilt pressure signal; a displaying device including a plurality of displaying elements to indicate the load condition of said forklift truck in a coordinate system having at least two axes, said displaying device providing a border line in said coordinate system to indicate a predetermined overload area; and a calculation control device calculating a weight of said cargo and a centroid position of the same based on said lift pressure signal and said tilt pressure signal, said calculation control device selectively actuating said displaying elements to indicate a position in said coordinate system, said indicated position indicating the calculated cargo weight along one of said at least two axes as a first variable, and the calculated centroid position along the other of the same. - View Dependent Claims (4, 5, 6, 7, 8, 9)
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Specification