US3678758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure indicating and limiting instrument
Assignee: Frank W Murphy Manufacturer Inc
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Filing: 1971-07-23
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Granted: 1972-07-25
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Expires: 1991-07-23
Abstract
Abstract A pressure gauge utilizes a Bourdon tube and associated mechanical linkage to indicate pressure on a calibrated dial between predetermined limits. High pressure and low pressure limit switches are fixedly secured to a carrier having lost motion connections with the Bourdon tube and said linkage. Adjustable high pressure and low pressure stops on the face of the instrument positively interrupt the movement of the instrument pointer and thereby lock said linkage. Continued expansion or contraction of the Bourdon tube utilizes said lost motion connections with said switch carrier to operate the high pressure and low pressure limit switches in proper sequence. The principle of operation is also adaptable to Bourdon tube temperature gauges.
Inventors
- 👤 Charles R Lawrence
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:16
CPC Classifications
G; G01; G01L; G01L7/00; G01L7/02; G01L7/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
184 words
A pressure indicating and limiting instrument comprising a Bourdon tube gauge including a sweep pointer and a rotary shaft carrying the pointer, a pair of independently adjustable high pressure and low pressure stop elements in the path of movement of said pointer in the high pressure and low pressure directions, gearing connected with the pointer shaft to drive the pointer responsive to expansion or contraction of the Bourdon tube due to increases or decreases of pressure therein, a carrier link having lost motion connections with the Bourdon tube and said gearing to allow relative movements between the link, Bourdon tube and said gearing, a pair of high pressure and low pressure limit switches fixedly mounted on the carrier link and bodily movable therewith, and a pair of switch operators on the Bourdon tube and said gearing adapted to operate said switches in sequence when said stop elements arrest movement of said pointer in the high pressure and low pressure directions, said lost motion connections then allowing relative movements between said switches and switch operators caused by continued expansion or contraction of the Bourdon tube.
Claim 2
Dependent Claim
184 words
A pressure indicating and limiting instrument comprising a Bourdon tube gauge including a sweep pointer and a rotary shaft carrying the pointer, a pair of independently adjustable high pressure and low pressure stop elements in the path of movement of said pointer in the high pressure and low pressure directions, gearing connected with the pointer shaft to drive the pointer responsive to expansion or contraction of the Bourdon tube due to increases or decreases of pressure therein, a carrier link having lost motion connections with the Bourdon tube and said gearing to allow relative movements between the link, Bourdon tube and said gearing, a pair of high pressure and low pressure limit switches fixedly mounted on the carrier link and bodily movable therewith, and a pair of switch operators on the Bourdon tube and said gearing adapted to operate said switches in sequence when said stop elements arrest movement of said pointer in the high pressure and low pressure directions, said lost motion connections then allowing relative movements between said switches and switch operators caused by continued expansion or contraction of the Bourdon tube.
Claim 3
Dependent Claim
23 words
The structure of claim 1, and said lost motion connections comprising slots in the carrier link movably engaging said pair of switch operators.
Claim 4
Dependent Claim
42 words
The structure of claim 2, and said switch operators comprising a pair of screws mounted on the Bourdon tube and a part of said gearing and having shanks engaging through said slots and heads adapted to engage actuator pins of said switches.
Claim 5
Dependent Claim
17 words
THe structure of claim 3, and said pair of limit switches comprising single pole double throw switches.
Claim 6
Dependent Claim
63 words
The structure of claim 1, and said pair of stop elements comprising stop pins in the path of movement of said pointer in intersecting relation therewith, rotary sweep arms carrying said pins, and manual knobs secured to said sweep arms for turning them independently in opposite directions, said instrument having a transparent lens and said knobs journaled for rotation directly upon said lens.
Claim 7
Dependent Claim
56 words
The structure of claim 1, and said gearing comprising a spur gear on said pointer shaft directly driving the pointer shaft, a sector gear meshing with said spur gear, a pivoted arm carrying the sector gear, and a pivotal connection between said arm and carrier link, said pivotal connection comprising one of said lost motion connections.
Claim 8
Dependent Claim
35 words
The structure of claim 6, and the pivot of said arm being positioned between the ends of the arm and having an access spaced from and parallel to the axis of said pointer rotary shaft.
Claim 9
Dependent Claim
47 words
The structure of claim 7, and a support structure in the instrument for said pointer shaft and gearing including the pivot for said arm, said support structure being bodily adjustable circumferentially around the rotational axis of the pointer shaft and being lockable in the selected adjusted position.
Claim 10
Dependent Claim
60 words
The structure of claim 8, and said instrument including a housing for completely enclosing the Bourdon tube gauge, said gearing, carrier link and limit switches, a Bourdon tube mounting plate formed integral with the tube and secured to a wall of said instrument housing, and said support structure mounted on said mounting plate and being circumferentially adjustable and lockable thereon.
Claim 11
Dependent Claim
38 words
The structure of claim 9, and said support structure comprising an upper and lower pair of support plates forming spaced bearings for the rotary pointer shaft and a parallel pivot shaft for the arm carrying said sector gear.
Claim 12
Dependent Claim
52 words
The structure of claim 10, and an electrical junction block mounted on a wall of said housing and adapted to receive lead wires from said pair of limit switches and also enabling electrical connections to be made between said switches and an external device whose operation is being monitored by the instrument.
References Cited (Backward Citations)
US2741987A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |