US3884068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load sensing device
Assignee: INTERNATIONAL MEASUREMENT AND CONTROL Co
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Filing: 1974-03-12
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Granted: 1975-05-20
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Expires: 1994-03-12
Abstract
Abstract An improved load sensing system adapted to monitor both compressive and tension loads that are incurred in press members during a working cycle. The system includes a piezoelectric transducer that produces an electrical signal proportional to changes in stress in the force carrying member and an electrical load limiting and detection circuit responsive to such signals to detect or monitor the loads in said member. A switch coupling provided between the circuit and the terminals of the transducer is operable to selectively reverse the connection between the transducer terminals and the circuit input leads so that in one setting the circuit indicates and monitors increases in compressive stresses in the press member and in its reverse setting monitors decreases in compressive stresses and increases in tension stresses in the member.
Inventors
- 👤 Frank R Dybel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:53
CPC Classifications
G; G01; G01L; G01L5/00; G01L5/0061; G01L5/0076; G01L1/00; G01L1/16; Y; Y10; Y10S; Y10S73/00; Y10S73/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
An improved sensing device for monitoring stresses which are intermittently applied to and removed from a deformable body, comprising, a transducer fixed to said body and having a pair of output terminals, said transducer being adapted to produce electrical output signals upon compressive loading and unloading of said transducer, said output signals being proportional to the change in loading on said transducer and having a polarity during compressive loading that is opposite that during unloading, detector means having a pair of input leads for connection with said transducer output terminals, and switch means for selectively reversing the connection between said input leads and tranducer terminals.
Claim 2
Dependent Claim
105 words
An improved sensing device for monitoring stresses which are intermittently applied to and removed from a deformable body, comprising, a transducer fixed to said body and having a pair of output terminals, said transducer being adapted to produce electrical output signals upon compressive loading and unloading of said transducer, said output signals being proportional to the change in loading on said transducer and having a polarity during compressive loading that is opposite that during unloading, detector means having a pair of input leads for connection with said transducer output terminals, and switch means for selectively reversing the connection between said input leads and tranducer terminals.
Claim 3
Dependent Claim
40 words
The sensing device of claim 1 wherein said transducer output terminals have two pairs of output leads extending therefrom, and said switch means is operable to selectively connect said detector input leads to either of said pairs of output leads.
Claim 4
Dependent Claim
18 words
The sensing device of claim 1 in which a directional diode is coupled between said detector input leads.
Claim 5
Dependent Claim
70 words
The sensing device of claim 3 in which said detector means includes amplifying means coupled to said input leads for providing an output voltage which is linearly proportional to the voltage of the transducer signal, means coupled to said amplifying means for providing an output indication when said output voltage exceeds a predetermined threshold, and capacitive means coupled across said transducer for charging as stress is applied to said body.
Claim 6
Dependent Claim
229 words
An improved sensing device for detecting stresses applied to a deformable body, comprising a transducer including a pair of mounting means fixed to said body substantially in line with the stress to be detected, said transducer having a pair of output terminals and a piezoelectric material interposed between said mounting means for providing at said output terminals a DC signal having a voltage substantially proportional to the stress applied to said body, amplifying means having a pair of input leads, means coupling said transducer terminals to said amplifying means so that a transducer ouTput voltage produced from an increase in stress of said body is applied to said amplifying means and an output voltage produced from a decrease in stress in said body is blocked from said amplifying means, said coupling means being selectively operable to reverse the connection between said transducer terminals and said input leads so that an output voltage produced from an increase in stress in said transducer is blocked from said amplifying means and an output voltage produced from a decrease in stress of said transducer is applied to said amplifying means, said amplifying means providing an output voltage which is linearly proportional to the voltage applied thereto from said transducer signal, and detector means coupled to said amplifying means for providing an output indication in response to the output voltage of said amplifying means.
Claim 7
Dependent Claim
229 words
An improved sensing device for detecting stresses applied to a deformable body, comprising a transducer including a pair of mounting means fixed to said body substantially in line with the stress to be detected, said transducer having a pair of output terminals and a piezoelectric material interposed between said mounting means for providing at said output terminals a DC signal having a voltage substantially proportional to the stress applied to said body, amplifying means having a pair of input leads, means coupling said transducer terminals to said amplifying means so that a transducer ouTput voltage produced from an increase in stress of said body is applied to said amplifying means and an output voltage produced from a decrease in stress in said body is blocked from said amplifying means, said coupling means being selectively operable to reverse the connection between said transducer terminals and said input leads so that an output voltage produced from an increase in stress in said transducer is blocked from said amplifying means and an output voltage produced from a decrease in stress of said transducer is applied to said amplifying means, said amplifying means providing an output voltage which is linearly proportional to the voltage applied thereto from said transducer signal, and detector means coupled to said amplifying means for providing an output indication in response to the output voltage of said amplifying means.
Claim 8
Dependent Claim
18 words
The sensing device of claim 5 in which a directional diode is coupled between said amplifying input leads.
Claim 9
Dependent Claim
61 words
The sensing device of claim 6 in which a capacitive means is coupled across said transducer for charging as stress is applied to said body, and said detector means includes a limiting circuit that provides an output indication when said output voltage exceeds a predetermined threshold and an indicating circuit that indicates the proportional level of said amplifying means output voltage.
Claim 10
Dependent Claim
40 words
The sensing device of claim 6 in which said detector means includes an output relay, and relay control means coupled to said amplifying means and adapted to energize said relay when said transducer output signal exceeds a predetermined threshold voltage.
Claim 11
Dependent Claim
19 words
The sensing device in claim 5 in which said coupling means is a momentary double pull, double pole switch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |