US3868855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tachometer instrument
Assignee: Murphy Management Inc
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Filing: 1974-01-03
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Granted: 1975-03-04
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Expires: 1994-01-03
Abstract
Abstract A completely mechanical tachometer features simplicity, few moving parts, and ruggedness, to withstand the heavy vibrations produced by continuous duty stationary diesel engines and the like. The instrument pointer is actuated by a simple mechanical linkage under direct influence of a unique and simplified rotary centrifugal force operated unit. The unit embodies rocker plates and an associated bowed spring and the rocker plates directly activate the pointer driving linkage. The instrument may embody electrical contacts and/or a built-in switch to initiate engine shut-down or an alarm for over-speed or under-speed conditions.
Inventors
- 👤 Jr Frank W Murphy
- 👤 Lewis M Carlton
- 👤 Troy L Teague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 02:37
CPC Classifications
G; G01; G01P; G01P1/00; G01P1/04; G01P1/07; G01P1/08; G01P1/10; G01P3/00; G01P3/02; G01P3/16; G01P3/18; F; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
251 words
A tachometer comprising a primary support, a centrifugal fly ball assembly mounted for rotation on said support and adapted for connection with a rotary element of an engine or the like, said fly ball assembly including a rotary plate element having a flat face, a pair of opposed curved rocker plates engaging said flat face rockably, a bowed spring attached to the rotary plate element and also attached to the rocker plates and tensioned to maintain the exterior eNds of the rocker plates elevated and their interior ends depressed relative to said flat face, fly ball masses attached to the rocker plates, a reciprocatory drive button in engagement with the interior ends of the rocker plates and adapted to be shifted thereby when said interior ends are elevated in response to an increase in speed of rotation of the fly ball assembly, a support plate attached to said primary support in spaced relation to the rotary fly ball assembly, a pivoted tachometer pointer on said support plate adapted to sweep over a dial having a scale indicating rotational speed, and a drive mechanism for said pointer on said support plate including a crank element, a movement pin for the crank element arranged in engagement with said drive button to be actuated thereby, said support plate having a clearance opening for the movement pin, and a resilient member attached to said movement pin and raised and lowered by displacement of the movement pin and underlying said crank element and contacting the same.
Claim 2
Dependent Claim
251 words
A tachometer comprising a primary support, a centrifugal fly ball assembly mounted for rotation on said support and adapted for connection with a rotary element of an engine or the like, said fly ball assembly including a rotary plate element having a flat face, a pair of opposed curved rocker plates engaging said flat face rockably, a bowed spring attached to the rotary plate element and also attached to the rocker plates and tensioned to maintain the exterior eNds of the rocker plates elevated and their interior ends depressed relative to said flat face, fly ball masses attached to the rocker plates, a reciprocatory drive button in engagement with the interior ends of the rocker plates and adapted to be shifted thereby when said interior ends are elevated in response to an increase in speed of rotation of the fly ball assembly, a support plate attached to said primary support in spaced relation to the rotary fly ball assembly, a pivoted tachometer pointer on said support plate adapted to sweep over a dial having a scale indicating rotational speed, and a drive mechanism for said pointer on said support plate including a crank element, a movement pin for the crank element arranged in engagement with said drive button to be actuated thereby, said support plate having a clearance opening for the movement pin, and a resilient member attached to said movement pin and raised and lowered by displacement of the movement pin and underlying said crank element and contacting the same.
Claim 3
Dependent Claim
40 words
The structure of claim 1, wherein said resilient member is an elongated spring tongue having a free end projecting on one side of the movement pin and adapted during displacement by the movement pin to activate an electrical contact means.
Claim 4
Dependent Claim
77 words
The structure of claim 1, and said fly ball assembly further comprising a shaft having an axial extension above said flat face, and said drive button consisting of a sleeve element telescopically engaged with said axial extension and guided thereby during displacement by said rocker plates, the interior ends of the rocker plates projecting between said flat face and one end of the sleeve element and during rocking movement exerting a camming action on the sleeve element.
Claim 5
Dependent Claim
74 words
The structure of claim 1, and said bowed spring comprising a curved plate spring having a central opening through which the interior ends of the rocker plates project and side sections attached to the rotary plate element, said spring additionally comprising opposite end sections which overlie the rocker plates near their exterior ends and are attached thereto whereby the spring interconnects the pair of rocker plates and secures them to the rotary plate element.
Claim 6
Dependent Claim
28 words
The structure of claim 4, and a single pair of fastener elements serving to attach the spring end portions and said fly ball masses to the rocker plates.
Claim 7
Dependent Claim
26 words
The structure of claim 5, and the interior ends of the rocker plates being notched to accommodate said axial extension of the fly ball assembly shaft.
Claim 8
Dependent Claim
79 words
The structure of claim 3, and said primary support including a bottom wall having a central recess, a ball bearing mounted within said recess, said shaft having an enlargement below said rotary plate element and engaging the inner race of the ball bearing and serving to space the rotary plate element from said bottom wall, said primary support including an upstanding side wall surrounding said fly ball assembly below said support plate and having said support plate resting thereon.
Claim 9
Dependent Claim
33 words
The structure of claim 1, and an exterior casing for the tachometer attached to the primary support and enclosing the primary support, said fly ball assembly, said support plate, pointer and drive mechanism.
References Cited (Backward Citations)
US1313175A
Cited
US967168A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |