US3740757A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peak shock recorder
Assignee: Individual
•
Filing: 1971-12-01
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Granted: 1973-06-19
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Expires: 1991-12-01
Abstract
Abstract A recording accelerometer of the general type known as a reed gage, for recording the shock spectrum of mechanical shocks of relatively long rise time, such as earthquakes. A plurality of cantilever reeds, each carrying an inertial mass and a stylus, are mounted in an array. Each stylus is disposed to ''''scratch'''' or emboss an arcuate line-like record on a record plate. Each plate has four recording surface locations, two on each side. Mechanical keying means are provided to insure that each plate is in its proper location and orientation, so that there can be no error in identifying the records made by the respective reeds. The natural frequencies of the reeds may cover the approximate range 2 - 25 Hz in one-third-octave steps. The instrument has no moving parts except the reeds themselves and requires no source of electrical or other power, and so may stand by for many years after installation and still reliably produce a record when a shock incident occurs. The combination of stylus and recording surface is of a novel type which permits identification of the peak excursions of each of the individual oscillations of a stylus on any single trace, so permitting recovery of the entire amplitude vs. time history of its oscillation - the time information being available from knowledge of the natural frequency of the reed.
Inventors
- 👤 P Engdahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:38
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/24; G01V1/242; G01P; G01P1/00; G01P1/12; G01P1/127; G01P15/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
117 words
An instrument for recording transient acclerations, comprising: an array of substantially coplanar resonant reeds of progressively graded natural frequencies; a mass, a stylus suspension spring, and a stylus on the end portion of each said reed; and a separate stationary substantially rigid record plate disposed in mechanical recording relation to each shaid stylus and substantially parallel to its plane of oscillation, each said stylus being adapted to make a main oscillatory record on said plate solely in the form of a single embossed-like arcuate line, and each said record plate having an embossable surface adapted to make detectible the position along said line of the terminus of an individual peak excursion of oscillatory motion of said stylus.
Claim 2
Dependent Claim
117 words
An instrument for recording transient acclerations, comprising: an array of substantially coplanar resonant reeds of progressively graded natural frequencies; a mass, a stylus suspension spring, and a stylus on the end portion of each said reed; and a separate stationary substantially rigid record plate disposed in mechanical recording relation to each shaid stylus and substantially parallel to its plane of oscillation, each said stylus being adapted to make a main oscillatory record on said plate solely in the form of a single embossed-like arcuate line, and each said record plate having an embossable surface adapted to make detectible the position along said line of the terminus of an individual peak excursion of oscillatory motion of said stylus.
Claim 3
Dependent Claim
52 words
An instrument as in claim 1, further comprising: slots in the frame of said instrument adapted to slidably receive each of said record plates, designations on said slots and on said plates, and keying means to prevent normal operation of said instrument when any said plate occupies any slot of non-matching designation.
Claim 4
Dependent Claim
37 words
The instrument of claim 2, wherein: said slots are adapted to receive said plates in positions substantially short of complete insertion, whereby damping trace records of said reels may be obtained parallel to said main oscillatory records.
Claim 5
Dependent Claim
35 words
An instrument as in claim 2, wherein: said keying means comprises notches in said plates each located according to the designation of that plate, and means to engage said notches correspondingly located in said instrument.
Claim 6
Dependent Claim
88 words
The instrument of claim 4, wherein: said pins are precisely located in the instrument frame and fit snugly into said slots, whereby said pins serve as accurate locating means for said plates along the direction of said record. 6 An instrument as in claim 1, wherein: each said plate has a plurality of recording positions determined by its orientation, each said plate fitting into said slots in a plurality of said orientations, and each said plate is provided with indexer keying means keyed by distinguish among said orientations.
Claim 7
Dependent Claim
63 words
An instrument as in claim 6, wherein: said indexer keyng means comprises notches in each of said record plates, and a movable indexer plate having an indexer member engageable with said notches; said indexer member being disposed generally perpendiculary to the plane of said plates and being engageable with all said notches in all said plates only when all said notches are aligned.
Claim 8
Dependent Claim
40 words
The instrument of claim 7 wherein: the case of said instrument is provided with a viewing hole opposite a portion of said indexer plate, and said plate is provided with record plate orientation designations which are visible through said hole.
Claim 9
Dependent Claim
31 words
An instrument as in claim 1, wherein: the tip of each said stylus lies substantially on the axis of natural torsional oscillation of the combination of said reed and said mass.
Claim 10
Dependent Claim
30 words
The instrument of claim 1, whErein: each said record plate is plated with a layer of a relatively hard metal, and then a thin layer of a relatively soft material.
Claim 11
Dependent Claim
66 words
An instrument as in claim 1 for operation with the plane of said reeds substantially horizontal for recording the vertical components of accelerations, said reeds being subject to static gravitational bending forces, wherein: all said reeds are pre-bent to a degree to make them lie substantially straight when subjected to said forces, said reeds thereby having each substantially the same natural frequency as before being pre-bent.
Claim 12
Dependent Claim
65 words
An instrument as in claim 1, further comprising: a case having mountmounting means for the root ends of said reeds, and means for removably mounting said record plates in recording relation to said styli; a cover removably fixable to anoopen portion of said case adjacent said plaes; indicia on said cover; and mechanical locating elements permitting installation of said over only in a predetermined orientation.
Claim 13
Dependent Claim
58 words
An instrument as in claim 12, further comprising: gasketing means and retractable fasteners adapted to attach said cover removably to said case with a substantially hermetic seal, and a screw in said cover adapted to be screwed inward against a portion of said case to exert a force to break said seal, to facilitate removal of said cover.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |