US4677579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suspended load measurement system
Assignee: BECOR WESTERN Inc SOUTH MILWAUKEE WI A CORP OF DE
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Filing: 1985-09-25
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Granted: 1987-06-30
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Expires: 2005-09-25
Abstract
Abstract A power shovel for surface mining operations is equipped with a Suspended Load Measuring (SLM) system. The SLM system determines the net weight of the material in the shovel bucket by sensing the electrical parameters of the drive motors. A microprocessor inputs the drive motor electrical parameters and processes them according to the known geometry of the power shovel. To meet the requisite accuracy of ±2% for a load measuring system to be effective, the SLM system utilizes a dynamic model which accounts for both conservative and nonconservative dynamic effects prevalent in power shovel operation. Correction are included for the conservative effects of the rotational inertia of the drive motors and reduction gear train, the stretch of the cables, and the inertia of the bucket. Non-conservative losses due to friction, gear loss and motor inefficiency are also compensated for. During truck loading operations, the SLM system maintains a cumulative total of the net weight of material in the truck based on the individual weights of each shovel bucket load. The total weight in the truck is then displayed to the power shovel operator so that the truck can be accurately loaded to full capacity.
Inventors
- 👤 Donald Radomilovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:28
CPC Classifications
G; G01; G01G; G01G19/00; G01G19/14; G01G19/18; E; E02; E02F; E02F9/00; E02F9/26; G01G9/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
128 words
A suspended load measurement system for determining the load weight moved by large mining and hoisting machinery such as excavators and cranes, the machinery having electric drive motors, mechanical drive means and cables attached to a load support for moving the load weight, the suspended load measurement system comprising: sensing means to determine the position of said load support; means responsive to said sensing means to determine the vertical component of the linear acceleration of said load support; and means responsive to said sensing means to determine the vertical component of the force required to effect movement of said load support; and means to determine the net load weight by performing a dynamic calculation compensating said vertical component of the force for said vertical component of the acceleration.
Claim 2
Dependent Claim
128 words
A suspended load measurement system for determining the load weight moved by large mining and hoisting machinery such as excavators and cranes, the machinery having electric drive motors, mechanical drive means and cables attached to a load support for moving the load weight, the suspended load measurement system comprising: sensing means to determine the position of said load support; means responsive to said sensing means to determine the vertical component of the linear acceleration of said load support; and means responsive to said sensing means to determine the vertical component of the force required to effect movement of said load support; and means to determine the net load weight by performing a dynamic calculation compensating said vertical component of the force for said vertical component of the acceleration.
Claim 3
Dependent Claim
36 words
The system of claim 1 wherein said means to determine the vertical component of the linear acceleration of said load support includes means to determine the speed of the electric drive motors and the cable acceleration.
Claim 4
Dependent Claim
33 words
The system of claim 1 wherein said means to determine the vertical component of the force required to effect movcement includes means to determine the torques and speeds of the electric drive motors.
Claim 5
Dependent Claim
24 words
The system of claim 2 wherein said large industrial machinery is a power shovel and said electric drive motors power hoist and crowd functions.
Claim 6
Dependent Claim
24 words
The system of claim 3 wherein said large industrial machinery is a power shovel and said electric drive motors power hoist and crowd functions.
Claim 7
Dependent Claim
42 words
The system of claim 1 wherein said means to determine said vertical components of the linear acceleration and force include means to correct for conservative losses of rotational inertia of the motors, reduction gear train, stretch of the cables and bucket inertia.
Claim 8
Dependent Claim
34 words
The system of claim 6 wherein said means to determine said vertical components of the linear acceleration and force include means to correct for non-conservative losses due to friction, gear loss and motor inefficiency.
Claim 9
Dependent Claim
18 words
The system of claim 7 further including means to determine the weight of the machinery cables and bucket.
Claim 10
Dependent Claim
15 words
The system of claim 1 including means to determine the operating mode of the machinery.
Claim 11
Dependent Claim
90 words
In a suspended load measurement system for mining or large hoisting machinery comprising a load support and operating systems to move the load support vertically and laterally, the operating systems including electric drive motors, mechanical drive means and cables attached to the load support, the load measurement system comprising: dynamic model means to provide compensated forces and linear accelerations of the mechanical drive means; means to continuously locate the load support; and means to continuously determine the drive motor operating parameters including the current and voltage of the drive motors.
Claim 12
Dependent Claim
90 words
In a suspended load measurement system for mining or large hoisting machinery comprising a load support and operating systems to move the load support vertically and laterally, the operating systems including electric drive motors, mechanical drive means and cables attached to the load support, the load measurement system comprising: dynamic model means to provide compensated forces and linear accelerations of the mechanical drive means; means to continuously locate the load support; and means to continuously determine the drive motor operating parameters including the current and voltage of the drive motors.
Claim 13
Dependent Claim
23 words
The system of claim 10 wherein said dynamic model means includes means to ascertain conservative and nonconservative losses of each said drive motor.
Claim 14
Dependent Claim
18 words
The system of claim 11 wherein said conservative and nonconservative losses include inertia, mechanical losses and cable stretch.
References Cited (Backward Citations)
US4500969A
Cited
US4553618A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |