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US 4,356,638 AGranted
Lift truck digital inclinometer
AssigneeLeveling Devices, Inc.
InventorsWilliam F. McKenna, Gerry A. Cwienkala
Life of this patent
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AssigneeLeveling Devices, Inc.
InventorsWilliam F. McKenna, Gerry A. Cwienkala
Estimating the term…
Apparatus for digitally displaying inclination of a lift truck mast includes an inertial inclination sensor carried by the mast and a digital display module for operator viewing remote from the mast. The inclination sensor includes a disc pendulum pivoted for damping its movement, the disc having a wand extending from it for exaggerated movement about the pivot. A plurality of light responsive devices are provided for detecting the position of the wand for the purpose of determining the degrees of actual mast inclination with respect to a true vertical gravitational plumb line. A logic circuit interconnected with these devices decodes signals resulting from a predetermined pattern of illumination on them produced by the wand representative of the mast inclination, providing an encoded signal which is converted to display drive signals for driving a plurality of digital display devices of numeric readout, providing operator display of the actual degrees and increments of degrees of mast inclination from the vertical plumb line.
Apparatus for displaying inclination from vertical of a lift truck mast or other vehicle structure, said apparatus comprising an inclination sensor module carried by said mast and an inclination display module remote from said mast for displaying to an operator the inclination of said mast, and characterized by said sensor module including a mass for inertially establishing a true vertical gravitational plumb line, means for pivotally securing said mass by providing a pivot axis extending through said mass for permitting pivoted movement thereof with respect to said mast with a minimized total period of oscillation, means for optically detecting the position of said mass relative to said mast, and means for converting the optically detected position to electronic signals to produce encoded signals, said display module comprising a display device responsive to said encoded signals providing display of the actual degrees and increments of degrees of inclination of said mast referenced to said vertical plumb line.
Apparatus for providing a digital display of the inclination from vertical of a lift truck or other vehicular structure, said apparatus comprising an inclination sensor module carried by said structure and a digital display module remote from said structure for digitally displaying to an operator the inclination of said structure, and characterized by said sensor module including a mass pivotally secured with respect to said structure for inertially establishing a true vertical gravitational plumb line, means for optically detecting the position of said mass relative to said structure, means for converting the optically detected position to electronic position signals, means for decoding said electronic position signals to produce encoded signals, said display module comprising a digital display device responsive to said encoded signals providing display of the actual degrees and increments of degrees of inclination of said structure referenced to said vertical plumb line.
Apparatus for providing a digital display of the actual degrees and increments of degrees of inclination from a true vertical gravitational plumb line of a lift truck mast, said apparatus comprising an inclination sensor module carried by said mast and a display module remote from said mast for providing said digital display to an operator, and characterized by said inclination sensor module including an enclosure adapted for securement to said mast, a pendulum positioned within said closure, said pendulum comprising a mass, a pivot defining a pivot axis extending through said mass for permitting swinging within said enclosure upon inclination of said mast from said vertical plumb line, said pivot axis being spaced from the center of said mass whereby a part of said mass is located above said pivot axis and a part of said mass is located below said pivot axis, and such that the center of gravity of said mass is located beneath said pivot axis, a wand extending from said mass and having mass-remote end providing exaggerated movement in response to movement of the center of gravity of said mass with respect to said pivot axis, a plurality of light responsive devices positioned with respect to the mass-remote end of said wand for detecting the position of said wand, said light responsive devices being fewer in number than the number of degrees and increments of degrees to be displayed, at least one light source for providing illumination for being received by said light responsive devices, said mass-remote end of said wand being configured to cause different ones of said light responsive devices to be illuminated in a predetermined pattern in response to pivoting of said mass about said pivot axis upon increase in the degree of inclination of said mast from said vertical plumb line, circuit means interconnected with said light responsive devices for providing decoding of signals from said light responsive devices resulting from said predetermined pattern of illumination to produce an encoded signal representative of the actual inclination of said vertical mast from said vertical plumb line, said display module comprising a plurality of digital display devices defining a numeric readout having a plurality of digits for indicating said actual degrees and increments of degrees of inclination, and means for converting said encoded signal to display drive signals for driving said display devices thereby to cause display by said digital readout by the actual degrees and increments of degrees of inclination of said mast from said vertical plumb line.
Dependencies are inferred from the claim text.