Apparatus and method for weighing moving objects
AssigneeWestinghouse Electric Corp.
InventorsAnthony T. Nasuta, Jr., Dale H. Brown
Life of this patent
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Abstract
Apparatus and method for measuring the weight of an object such as a letter, magazine or parcel, while the object is in motion, without using a weighing scale. The apparatus and method disclosed make use of moving, preferably vertically-oriented transport belts driven by a constant velocity, closed-loop feedback system which includes an electric motor. An object to be weighed is engaged and lifted upwards by the moving belts, increasing the load on the motor as a function of the weight of the object. The increased motor current evoked by the lifted object can be processed to extract the object's weight.
Claims12
An apparatus for weighing an object in transit from a first position to a second position comprising:
- (a) a conveyor operable to transport said object in contact with said conveyor from said first position to said second position;
- (b) an electric motor operatively connected to said conveyor, continuously driving said conveyor so that said object travels through said first position to said second position;
- (c) control means connected to said electric motor for operatively controlling said motor so that said object is generally transported by said conveyor at a preselected velocity during a portion of travel from said first position to said second position;
- (d) sensing means for sensing a motor drive current of said electric motor;
- and
- (e) processing means operatively connected to said sensing means for calculating a weight of said object based on said motor drive current.
A method of weighing an object in transit from a first position to a second position comprising the following steps:
- (a) transporting said object substantially vertically from said first position to said second position so as to oppose gravitational force;
- (b) compelling said transporting of said object with an electric motor;
- (c) controlling said electric motor so that said object is generally transported at a preselected velocity during a portion of travel from said first position to said second position;
- (d) sensing motor drive current of said electric motor;
- and
- (e) calculating a weight of said object from said motor drive current of said electric motor.
Dependencies are inferred from the claim text.