US3873067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel injector depressor tool
Assignee: Individual
•
Filing: 1974-03-13
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Granted: 1975-03-25
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Expires: 1994-03-13
Abstract
Abstract Disclosed is a lever type tool for depressing the fuel injector plungers of a diesel engine to test the engine for cylinder misfiring. Change in engine sound after depression of the plunger denotes a properly firing cylinder. Lack of change in engine sound denotes an improperly firing cylinder. The plungerdepressing tool is formed with a hook which is adapted to partially encircle the mounting shaft for an injector rocker arm, whereby the tool is enabled to be swung about the rocker arm pivot axis without slipping out of position. The plunger-engaging surface of the tool is an arcuate surface having a radius of curvature that causes the tool to continually engage the plunger at points near a central radial plane of the plunger.
Inventors
- 👤 Raul M Carpio
- 👤 Ernesto J Alarcon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:48
CPC Classifications
F; F02; F02M; F02M61/00; F02M61/14; B; B25; B25B; B25B27/00; B25B27/0035; F02B; F02B3/00; F02B3/06; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53552; Y10T29/53561; Y10T29/53578
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A fuel injector depresser tool comprising arcuate hook means adapted to partially encircle a fuel injector rocker arm shaft to temporarily mount the tool for arcuate motion around the shaft axis; presser means having a surface adapted to engage the end face of a fUel injector plunger for depressing same to the cylinder misfire position, and a manually operated handle for effecting arcuate movement of the tool around the shaft axis; said hook means having an arcuate shaft-engagement surface measuring at least approximately 150* around the shaft axis for preventing inadvertant shifting of the tool relative to the shaft when the presser means is engaged with the plunger.
Claim 2
Dependent Claim
108 words
A fuel injector depresser tool comprising arcuate hook means adapted to partially encircle a fuel injector rocker arm shaft to temporarily mount the tool for arcuate motion around the shaft axis; presser means having a surface adapted to engage the end face of a fUel injector plunger for depressing same to the cylinder misfire position, and a manually operated handle for effecting arcuate movement of the tool around the shaft axis; said hook means having an arcuate shaft-engagement surface measuring at least approximately 150* around the shaft axis for preventing inadvertant shifting of the tool relative to the shaft when the presser means is engaged with the plunger.
Claim 3
Dependent Claim
47 words
The tool of claim 1 wherein the plunger-engagement surface is an arcuate surface centered on an imaginary axis parallel to the axis defined by the aforementioned shaft-engagement surface; an imaginary bisect plane taken through the arcuate shaft-engagement surface being perpendicular to a line interconnecting the two axes.
Claim 4
Dependent Claim
35 words
The tool of claim 2 wherein the radius of curvature of the plunger-engagement surface is approximately one third the length of the lever arm measured from the rocker arm shaft axis to the plunger-engagement surface.
Claim 5
Dependent Claim
19 words
The tool of claim 1 wherein the hook means and presser means define a structure having a serpentine shape.
Claim 6
Dependent Claim
19 words
The tool of claim 4 wherein the presser means has a lesser radius of curvature than the hook means.
Claim 7
Dependent Claim
21 words
The tool of claim 1 wherein the hook means and presser means are formed from bar stock into a serpentine configuration.
Claim 8
Dependent Claim
29 words
The tool of claim 1 wherein the plunger-engagement surface is an arcuate surface having a radius of curvature slightly less than the radius of curvature of the shaft-engagement surface.
Claim 9
Dependent Claim
25 words
The tool of claim 1 wherein the shaft-engagement surface and plunger-engagement surface are oppositely directed to exert oppositely acting forces on the shaft and plunger.
Claim 10
Dependent Claim
27 words
The tool of claim 1 wherein the hook means and presser means are constructed as a fork structure adapted to straddle the rocker arm of the engine.
Claim 11
Dependent Claim
19 words
The tool of claim 9 wherein the fork structure is formed from a single length of rectangular bar stock.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |