Optical digital sensor for crane operating aid
First Claim
1. In a crane including a first portion and a second portion, said portions being operably moveable with respect to one another, an absolute encoding digital optical sensor comprising:
- detector means associated with one of said portions and including an array of light emitting elements;
encoder means associated with the other of said portions and operative to optically impart digitally encoded information to said detector means representative of the displacement between said portions;
means operative to energize a series connected plurality of said light emitting elements; and
a fault detection circuit operative to maintain a constant current through said series connected plurality of light emitting elements and to generate a fault condition signal operative to deenergize all of the light emitting elements within said array upon detecting a failure of any one of said light emitting elements.
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Accused Products
Abstract
A crane operating aid comprises a load moment computer and a number of sensors which monitor crane parameters, such as boom length, boom angle, slewing angle, and boom reaction forces. The computer then calculates the percentage of load capacity as a function of the crane manufacturer'"'"'s published load rating tables. Absolute encoding digital optical sensors are employed to monitor linear or angular displacement between portions of the crane which are operatively moveable with respect to one another. The digital output signals from the various sensors are then fed to the computer for use in its calculations. Each sensor comprises a detector made up of a light emitting element which is spaced from a light receiving element and an encoder disc which is mounted for displacement with respect to the detector and operates to present a series of tracks intermediate the light emitting portion and light receiving portion of the detector. Each track comprises a series of alternatingly opaque and transparent portions. By moving the encoder disc with respect to the detector, digitally encoded information is imparted to the detector representative of the displacement of the portions of the crane being monitored. An outage detector monitors the light emitting portion of the detector and generates a fault condition signal upon the failure of any of the light sources within the light emitting portion.
60 Citations
24 Claims
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1. In a crane including a first portion and a second portion, said portions being operably moveable with respect to one another, an absolute encoding digital optical sensor comprising:
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detector means associated with one of said portions and including an array of light emitting elements; encoder means associated with the other of said portions and operative to optically impart digitally encoded information to said detector means representative of the displacement between said portions; means operative to energize a series connected plurality of said light emitting elements; and a fault detection circuit operative to maintain a constant current through said series connected plurality of light emitting elements and to generate a fault condition signal operative to deenergize all of the light emitting elements within said array upon detecting a failure of any one of said light emitting elements. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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2. In a crane including a first portion and a second portion, said portions being operably moveable with respect to one another, a crane operating aid comprising:
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detector means associated with one of said portions and including an array of light emitting elements; encoder means associated with the other of said portions and operative to optically impart digitally encoded information to said detector means representative of the displacement between said portions; means operative to energize a series connected plurality of said light emitting elements; a fault detection circuit operative to maintain a constant current through said series connected plurality of light emitting elements and to generate a fault condition signal operative to deenergize all of the light emitting elements within said array upon detecting a failure of any one of said light emitting elements; and operator interface means operative to receive said digitally encoded information and generate a sensible crane condition signal as a function thereof. - View Dependent Claims (16, 17, 18, 19, 20)
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3. In a crane including an upper mounted for rotation upon a lower and a boom pivotally mounted upon said upper, a crane operating aid comprising:
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a first absolute encoding digital optical sensor operative to monitor the slewing angle between said upper and lower and to generate a slewing angle data signal as a function thereof; a second absolute encoding digital optical sensor operative to monitor the luffing angle between said boom and upper and to generate a luffing angle data signal as a function thereof; and operative interface means operative to receive said signals and to generate sensible crane condition signals as a function thereof;
each said sensor comprisingdetector means including an array of light emitting elements; encoder means operative to optically impart digitally encoded information to said detector means representative of the displacement therebetween; means operative to energize a series connected plurality of said light emitting elements; and a fault detection circuit operative to maintain a constant current through said series connected plurality of light emitting elements and deenergize all of the light emitting elements within all of said sensors upon detecting a failure of any one of said light emitting elements. - View Dependent Claims (21, 22, 23, 24)
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Specification