US3826321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load weighing system for cranes with rotatable booms
Assignee: TRANS SONICS Inc
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Filing: 1973-05-25
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Granted: 1974-07-30
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Expires: 1993-05-25
Abstract
Abstract A load weighing system for a crane having a boom which is independently rotatable with respect to an operator''s cab carrying an indicator for displaying the load weight. The system uses a boom-mounted dynamometer whose output is an accurate indication of cable tension and therefore load weight. The dynamometer output modulates a transmitter and the transmitter output is fed to a loop around the boom pedestal. The resulting magnetic field surrounding the loop provides a medium for coupling the transmitted signal to the cab-mounted receiver.
Inventors
- 👤 B Edgerton
- 👤 E Rigney
- 👤 R Benson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:52
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/04; G01L5/10; G01L5/106; B; B66; B66C; B66C13/00; B66C13/16; G01G; G01G19/00; G01G19/14; G01G19/18; G01G3/00; G01G3/12; G01G3/14; G01G3/1402; G01G3/1406; G01G3/142; G01L5/102; G01L5/107
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
156 words
A load weighing system for a crane having a boom continuously rotatable about a fixed pedestal on the crane body, comprising: A. signal generating means for mounting said boom to generate a load signal indicative of the weight of a load lifted by said boom, B. boom antenna means for mounting on said boom to form an antenna coil encircling said pedestal, C. means responsive to said load signal for electrically energizing said boom antenna means with a signal indicative of said load signal, D. a body antenna for mounting adjacent said pedestal on said body and inductively coupled to said coil to receive signals therefrom, E. a receiver for mounting on said body and connected to receive signals from said body antenna, and F. an indicator for mounting on said body and connected to said receiver for displaying an indication of the weight of the load in response to signals received by said body antenna.
Claim 2
Dependent Claim
156 words
A load weighing system for a crane having a boom continuously rotatable about a fixed pedestal on the crane body, comprising: A. signal generating means for mounting said boom to generate a load signal indicative of the weight of a load lifted by said boom, B. boom antenna means for mounting on said boom to form an antenna coil encircling said pedestal, C. means responsive to said load signal for electrically energizing said boom antenna means with a signal indicative of said load signal, D. a body antenna for mounting adjacent said pedestal on said body and inductively coupled to said coil to receive signals therefrom, E. a receiver for mounting on said body and connected to receive signals from said body antenna, and F. an indicator for mounting on said body and connected to said receiver for displaying an indication of the weight of the load in response to signals received by said body antenna.
Claim 3
Dependent Claim
44 words
A load weighing system according to claim 1 in which said energizing means comprises a transmitter mounted on said boom which emits a signal indicative of the load signal and in which said loop comprises a multi-turn electrically conductive wire connected to said transmitter.
Claim 4
Dependent Claim
30 words
a stationary receiving antenn, fixed to said carrier body adjacent said coil and inductively couple thereto, said antenna applying to said receiver signals transmitted from said transmitter through said coil.
Claim 5
Dependent Claim
30 words
a stationary receiving antenn, fixed to said carrier body adjacent said coil and inductively couple thereto, said antenna applying to said receiver signals transmitted from said transmitter through said coil.
Claim 6
Dependent Claim
36 words
a second input derived from said oscillator and indicative of the oscillator frequency, providing as output the integral of the difference of said inputs, and C. means connecting said integrator output as input to said oscillator.
Claim 7
Dependent Claim
36 words
a second input derived from said oscillator and indicative of the oscillator frequency, providing as output the integral of the difference of said inputs, and C. means connecting said integrator output as input to said oscillator.
Claim 8
Dependent Claim
35 words
A load weighing system according to claim 2 in which saiD load signal generating means includes a strain gage transducer having a tensile bar mounted to sense the tension in a cable supporting said load.
Claim 9
Dependent Claim
65 words
A load weighing system according to claim 3 in which said load signal generating means comprises a dynamometer having a pair of outer pulleys freely rotating about parallel spaced axes and guiding said cable and an inner pulley freely rotating about an axis parallel to said inner pulley axes, axially offset thereform, having said tensile bar forming the hub thereof, and pressing against said cable.
Claim 10
Dependent Claim
45 words
A load weighing system according to claim 4 in which said tensile bar is supported on a mounting plate in cantilever manner and has a plurality of strain gages mounted thereon for sensing strain in said bar due to pulley deflection caused by said load.
Claim 11
Dependent Claim
40 words
A load weighing system according to claim 5 in which said energizing means includes a voltage controlled oscillator whose frequency varies in accordance with the load sensed by said dynamometer, the output of said oscillator being applied to said loop.
Claim 12
Dependent Claim
32 words
A load weighing system according to claim 6 in which said receiver includes a phase lock loop providing an output indicative of the frequency variation of signals detected in said body antenna.
Claim 13
Dependent Claim
101 words
For a crane having a cable for lifting a load, the improvement comprising a load weighting system having: A. means for sensing tension in the cable to thereby provide a signal indicative of the weight of said load B. a transmitter providing an output whose frequency varies in response to said signal, C. a receiver remote from said transmitter and responsive to the frequency of signals received therefrom to provide an output indicative of the weight of said load, and D. inductively coupled antennas connected respectively to the transmitter and to the receiver for coupling the transmitter output to said receiver.
Claim 14
Dependent Claim
101 words
For a crane having a cable for lifting a load, the improvement comprising a load weighting system having: A. means for sensing tension in the cable to thereby provide a signal indicative of the weight of said load B. a transmitter providing an output whose frequency varies in response to said signal, C. a receiver remote from said transmitter and responsive to the frequency of signals received therefrom to provide an output indicative of the weight of said load, and D. inductively coupled antennas connected respectively to the transmitter and to the receiver for coupling the transmitter output to said receiver.
Claim 15
Dependent Claim
34 words
A crane load weighing system according to claim 8 in which said transmitter comprises: A. an oscillator whose frequency varies in response to inputs applied thereto, B. an integrator having applied as inputs thereto:
Claim 16
Dependent Claim
36 words
A crane load weighing system according to claim 9 in which said tension sensing means includes a plurality of strain gages responsive to said cable tension and connected to provide said first input to said integrator.
Claim 17
Dependent Claim
46 words
A crane load weighing system according to claim 9 in which said sensing means includes first and second series connected strain gages having a reference potential applied thereto and providing an output at a common connection point for application to said integrator as said first input.
Claim 18
Dependent Claim
56 words
A crane load weighing system according to claim 9 which includes a frequency to voltage converter for generating said second input, said converter comprising: A. a potential source B. an integrator, and C. switching means operable to alternately connect said source to said integrator and disconnect it therefrom in response to the output of said oscillator.
Claim 19
Dependent Claim
32 words
A crane load weighing system according to claim 12 in which the reference potential applied to the strain gages is obtained from the potential source included in said frequency to voltage converter.
Claim 20
Dependent Claim
85 words
A crane load weighing system according to claim 8 in which said receiver includes: A. means for generating a direct current signal whose magnitude is proportional to the difference between the transmitter output frequency and a local reference frequency corresponding to a no-load condition B. an amplifier whose gain is settable in accordance with the parts of line of said cAble, C. means connecting said direct current signal as input to said amplifier, and D. an indicator connected to receive the output of said amplifier.
Claim 21
Dependent Claim
36 words
A crane load weighing system according to claim 14 which includes switching means actuable to establish a predetermined gain for said settable gain amplifier to establish a defined output in the absence of an actual load.
Claim 22
Dependent Claim
89 words
A crane load weighing system according to claim 14 in which the direct current signal connecting means includes means for generating a direct current reference signal corresponding to said reference frequency and which further includes a second amplifier to which said direct current reference signal is applied as an input, said indicator being connected in series with the outputs of both said settable gain amplifier and said second amplifier to thereby provide an output indicative of the difference between said direct current signal and said direct current reference signal.
Claim 23
Dependent Claim
42 words
A crane load weighing system according to claim 16 which further includes a potentiometer interposed between said direct current reference signal generating means and said second amplifier such that only a selected portion of said reference signal is applied to said amplifier.
Claim 24
Dependent Claim
53 words
A crane load weighing system according to claim 16 which includes: A. an amplifier for amplifying the signal applied to the receiver, B. a limiter connected to limit the output of said amplifier to within predetermined limits, and C. means connecting the output of said limiter to said direct current signal connecting means.
Claim 25
Dependent Claim
58 words
A crane load weighing system according to claim 18 in which said crane has a load-lifting boom carrying said cable and mounted for unrestricted rotation about a pedestal on a carrier body, and in which A. said transmitter is mounted on said boom, B. said receiver is mounted on said carrier body, and C. said coupling means comprises
Claim 26
Dependent Claim
129 words
A crane load weighing system according to claim 8 in which said cable tension sensing means comprises a dynamometer having A. a base plate for mounting adjacent a portion of said cable, B. first second and third rotating pulleys mounted on said base plate for rotating contact with said cable, in a common plane of contact, and having axes of rotation perpendicular to said plate, C. said third pulley being positioned intermediate said first and second pulleys with its rotational axis offset from a line joining the rotational axis of said first and second pulleys and being mounted on a shaft cantilevered from said plate and having strain gages thereon for sensing strain in said shaft caused by tension transmitted to the shaft through said pulley from the cable.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |