US4405024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Weighing devices
Assignee: SINAR AGRITEC Ltd
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Filing: 1980-12-08
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Granted: 1983-09-20
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Expires: 2000-12-08
Abstract
Abstract A weighing device uses frequency measurement to determine weight. One body (3; 23; 68) is of known mass and another body (8; 28; 66) also of known mass is spring (9; 29; 83) connected to it. This body carries the load whose mass is to be determined. Both bodies can oscillate in one mode in an effectively isolated system, being carried by springs (2, 13; 22, 33; 65, 67) from a support (1; 21; 60, 62). The oscillations are electromagnetically generated, but when a certain amplitude is attained the drive is cut off and the system resonates freely. The frequency varies with the mass of the bodies, and so a load on one can be weighed by reference to the frequency, which can be detected through the electromagnetic means (12, 32, 76) which provided the initial drive pulses.
Inventors
- 👤 Robert H. Fraval
- 👤 Howerd P. Oakford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:13
CPC Classifications
G; G01; G01G; G01G3/00; G01G3/12; G01G3/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
145 words
A device for weighing a load of unknown mass comprising a first body (3; 23; 68) of known mass, a second body (8; 28; 66) of known mass adapted to carry a load of unknown mass, a base (1; 21; 60, 62), a suspension system in the form of matching spring means (2, 13; 22, 33; 65, 67) for each body supporting the bodies on the base for substantially unimpeded motion in one mode over at least a limited distance, and further spring means (9; 29; 83) connecting said bodies so that their natural oscillations are in said one mode and mutually opposed, whereby opposite forces are transmitted via the spring suspension means to the base and the bodies are substantially isolated from the environment, and means (12; 32; 76) for determining the resonant frequency of such oscillations and hence the mass of the load.
Claim 2
Independent Claim
145 words
A device for weighing a load of unknown mass comprising a first body (3; 23; 68) of known mass, a second body (8; 28; 66) of known mass adapted to carry a load of unknown mass, a base (1; 21; 60, 62), a suspension system in the form of matching spring means (2, 13; 22, 33; 65, 67) for each body supporting the bodies on the base for substantially unimpeded motion in one mode over at least a limited distance, and further spring means (9; 29; 83) connecting said bodies so that their natural oscillations are in said one mode and mutually opposed, whereby opposite forces are transmitted via the spring suspension means to the base and the bodies are substantially isolated from the environment, and means (12; 32; 76) for determining the resonant frequency of such oscillations and hence the mass of the load.
Claim 3
Dependent Claim
47 words
A device as claimed in claim 1, wherein pulse-operated electromagnetic means (7, 12; 27, 32; 74, 76) are provided for generating oscillations at a frequency approximating to the expected resonant frequency, there being means (47) for blocking the pulses prior to the determination of the resonant frequency.
Claim 4
Dependent Claim
27 words
A device as claimed in claim 2, wherein the electromagnetic means are arranged to produce, after the pulses are blocked, signals corresponding to the subsequent natural oscillations.
Claim 5
Dependent Claim
37 words
A device as claimed in claim 1, 2 or 3, wherein means (48, 49) are provided for determining a given amplitude of oscillations and, when this is achieved, for activating the means for determining the resonant frequency.
Claim 6
Dependent Claim
50 words
A device as claimed in claim 4, wherein pulse-operated electromagnetic means (7, 12; 27, 32; 74, 76) are provided for generating oscillations at a frequency, and are arranged to produce, during a fraction of the pulse cycle when a pulse is not present, an indication of the amplitude of oscillation.
Claim 7
Independent Claim
139 words
A method of weighing a load of unknown mass comprising: (i) supporting first and second bodies by respective matching spring means from a base in such manner that for one mode of movement they are substantially unimpeded at least over a limited distance, (ii) spring connecting said bodies so that the natural oscillations of said bodies are opposed and in said one mode, whereby opposite forces are transmitted by the spring supporting means to the base and the bodies are substantially isolated from the environment, (iii) determining the resonant frequencies of said oscillations over a range of ladings of said second body, (iv) lading said second body with a load of unknown mass, (v) causing the body/spring assembly to oscillate in said one mode, and (vi) determining from the resonant frequency of natural oscillations the mass of said load.
Claim 8
Independent Claim
139 words
A method of weighing a load of unknown mass comprising: (i) supporting first and second bodies by respective matching spring means from a base in such manner that for one mode of movement they are substantially unimpeded at least over a limited distance, (ii) spring connecting said bodies so that the natural oscillations of said bodies are opposed and in said one mode, whereby opposite forces are transmitted by the spring supporting means to the base and the bodies are substantially isolated from the environment, (iii) determining the resonant frequencies of said oscillations over a range of ladings of said second body, (iv) lading said second body with a load of unknown mass, (v) causing the body/spring assembly to oscillate in said one mode, and (vi) determining from the resonant frequency of natural oscillations the mass of said load.
Claim 9
Dependent Claim
32 words
A method as claimed in claim 6, wherein the oscillations are generated electromagnetically by pulses at a frequency approximating to the expected resonant frequency, these pulses being blocked prior to said determination.
Claim 10
Dependent Claim
32 words
A method as claimed in claim 7, wherein the pulses are applied to electromagnetic means which also serve, after the pulses are blocked, to produce signals corresponding to the subsequent natural oscillations.
Claim 11
Dependent Claim
25 words
A method as claimed in claim 6, 7 or 8, wherein said determination from the resonant frequency is carried out a given amplitude of oscillation.
Claim 12
Dependent Claim
51 words
A method as claimed in claim 9, wherein initially oscillations are generated electromagnetically by pulses at a frequency approximating to the expected resonant frequency, and during the fraction of the pulse cycle that a pulse is not present the electromagnetic means serve to provide an indication of the amplitude of oscillation.
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |