Elevator cab load measuring system
AssigneeOtis Elevator Company
InventorsAndrew J. Donofrio, John E. Gaines
Life of this patent
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Abstract
Transducers are located between the elevator cab and the supporting frame at points which lie along a line that passes through the cab center of deflection. These transducers produce an analog output whose magnitude varies proportionally with the force applied through the transducer to the cab. The outputs of the transducers are summed together and their actual sum corresponding to the empty car condition is subtracted from the sum of the outputs and the remainder is multiplied by the actual ratio between car weight and the sum of the transducer outputs. This yields the cab load.
Claims22
An elevator system wherein the cab is supported on a frame and passenger/duty load is determined by means of a system comprising:
- apparatus which is located between the cab and the frame and through which a portion of the overall cab supporting force is transmitted to at least one selected point on the cab, said apparatus generating a signal associated with each selected point, the magnitude of said signal manifesting the force transmitted therethrough to the cab, the location of the selected point or points being such that the total supporting force transmitted through the selected point or points is the same for a given weight regardless of the distribution of the weight in the cab, said apparatus including a force transducer at each selected point for generating said signal, and
- means responsive to the transducer signals and a signal reflecting the empty cab weight for providing a cab load signal reflecting the sum of all the signals from the transducers and for providing a passenger/duty load signal reflecting the difference between that cab load signal and the signal reflecting the empty cab weight.
An elevator system wherein a cab is supported resiliently on a frame at selected support points and car weight is determined by means of a load weighing system comprising:
- a transducer which is located between the cab and the frame and through which a cab supporting force is transmitted to a point on the cab, said transducer generating a signal having a magnitude that manifests the magnitude of the force transmitted therethrough to the cab, said point being located substantially at the cab center of deflection, and
- means responsive to the transducer signals and a signal reflecting the empty cab weight for providing a cab load signal reflecting the sum of all the signals from the transducers and for providing a passenger/duty load signal reflecting the difference between that cab load signal and the signal reflecting the empty cab weight.
An elevator system wherein a cab is supported resiliently on a frame at selected support points and cab weight is determined through the use of a load weighing system comprising:
- two transducers which are located between the cab and the frame and through which a cab supporting force is transmitted to two corresponding points on the cab, each transducer generating a signal having a magnitude reflecting the force transmitted through the transducer to its corresponding point on the cab, said transducers being located at opposite sides of the cab center of deflection and on a line that passes substantially through the center of deflection, and
- means responsive to the transducer signals and a signal reflecting the empty cab weight for providing a cab load signal reflecting the sum of all the signals from the transducers and for providing a passenger/duty load signal reflecting the difference between that cab load signal and the signal reflecting the empty cab weight.
An elevator system wherein the cab is supported on a frame and cab weight is determined through the use of a load weighing system which operates by:
- sensing a supporting force between the frame and the cab at selected points which are related in that the aggregate force supporting the cab at those points is the same regardless of the weight distribution in the cab, generating a signal which is proportional to the sensed force at each point, and
- summing said signals to provide cab load, then subtracting the empty cab load from the determined cab load to determine passenger/duty load.
A load weighing system for use in an elevator system wherein the cab is supported on a frame, said system comprising:
- apparatus which is located between the cab and the frame, said apparatus transmitting supporting force to the cab through at least one selected point on the cab and generating a signal associated with each selected point, the magnitude of the signal reflecting the force transmitted to its corresponding point, each point or points being selected so that the sum of the forces at the selected point or points is substantially the same for a given weight regardless of the distribution of the weight in the car, and
- means responsive to the transducer signals and a signal reflecting the empty cab weight for providing a cab load signal reflecting the sum of all the signals from the transducers and for providing a passenger/duty load signal reflecting the difference between that cab load signal and the signal reflecting the empty cab weight.
An elevator passenger load detecting system for use with a cab structure wherein the cab is supported in a frame to which the cab hoisting apparatus connects, said system comprising:
- two force responsive transducers which provide an output signal whose magnitude changes in proportion to the force applied by said transducers, said transducers being located between the frame and the cab along a line substantially through the cab's center of deflection, said transducers being oppositely located with respect to the center of deflection, and
- processing means for storing an estimated empty cab weight and estimated change in the sum of said signals between said estimated empty weight and an estimated full cab weight;
- for adding externally applied corrections to said store parameters every time passenger load is computed to generate an actual empty cab weight which equals the weight reflected by the sum of said signals for an empty cab, and a full cab weight which equals the weight reflected by said sum when the cab is actually full;
- for subtracting said actual empty weight from the weight reflected by said sum;
- for multiplying the remainder by a coefficient reflecting the ratio between the sum and the difference between said actual empty weight and said actual full cab weight, and
- adjustable means for generating said corrections.
Dependencies are inferred from the claim text.