US5258753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital engine analyzer
Assignee: Snap On Inc
•
Filing: 1991-10-18
•
Granted: 1993-11-02
•
Expires: 2011-10-18
Abstract
Abstract A digital engine analyzer has an oscilloscope display and is controlled by microprocessors operating under menu-driven stored program control. The analyzer receives analog input signals from an engine being analyzed. The engine calculates and displays real-time cylinder time balance information by calculating for each cylinder the cylinder time period from the firing of that cylinder to the firing of the next cylinder, storing the cylinder time values for each cylinder for a number of successive engine cycles, averaging the time period values for each cylinder over that number of engine cycles, calculating an overall average of the cylinder averages, calculating the percentage difference between each cylinder average and the overall average and then displaying the percentage differences in both numerical and bar graph form along with the overall average value.
Inventors
- 👤 Gary D. Jonker
- 👤 Craig F. Govekar
- 👤 Michael B. Meeker
- 👤 James R. Piehl
- 👤 Michael C. Putrow
- 👤 John C. Sniegowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:45
CPC Classifications
F; F02; F02P; F02P17/00; F02P17/02; F02P17/04; F02P17/08
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
198 words
In a system for analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the improvement comprising: sensing means coupled to the engine for sensing the firing voltage for each cylinder in a cylinder time period and producing a firing signal in response to each firing, processing means operating under stored program control and coupled to said sensing means and responsive to said firing signals for calculating for each cylinder a value representing its cylinder time period where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, said processing means including means for calculating an overall average of the cylinder time period values for all of the cylinders and for calculating the percentage difference between the cylinder time period value for each cylinder and the overall average, and display means coupled to said processing means for displaying for each cylinder the percentage difference between the cylinder time period value for that cylinder and the overall average.
Claim 2
Dependent Claim
198 words
In a system for analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the improvement comprising: sensing means coupled to the engine for sensing the firing voltage for each cylinder in a cylinder time period and producing a firing signal in response to each firing, processing means operating under stored program control and coupled to said sensing means and responsive to said firing signals for calculating for each cylinder a value representing its cylinder time period where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, said processing means including means for calculating an overall average of the cylinder time period values for all of the cylinders and for calculating the percentage difference between the cylinder time period value for each cylinder and the overall average, and display means coupled to said processing means for displaying for each cylinder the percentage difference between the cylinder time period value for that cylinder and the overall average.
Claim 3
Dependent Claim
34 words
The system of claim 1, wherein the engine includes ignition coil means coupled to each cylinder for providing an ignition voltage thereto, said sensing means including pickup means coupled to said ignition coil means.
Claim 4
Dependent Claim
61 words
The system of claim 1, and further comprising pickup means coupled to the first cylinder in the firing order for detecting the firing thereof, said processing means including means coupled to said pickup means for identifying the cylinder associated with each firing signal and for causing said display means to display immediately adjacent to each percentage difference a corresponding cylinder number.
Claim 5
Dependent Claim
25 words
The system of claim 1, wherein said processing means and said display means include means cooperating to provide a numerical display of the percentage differences.
Claim 6
Dependent Claim
14 words
The system of claim 4, herein said display means includes a cathode-ray tube monitor.
Claim 7
Dependent Claim
25 words
The system of claim 1, wherein said processing means said display means include means cooperating to display the cylinder time period value for each cylinder.
Claim 8
Dependent Claim
19 words
The system of claim 6, wherein said cylinder time period display is in the form of a bar graph.
Claim 9
Dependent Claim
31 words
The system of claim 1, wherein said processing means and said display means include means cooperating to provide a display of the average of all of the cylinder time period values.
Claim 10
Dependent Claim
230 words
In a system for analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the improvement comprising: sensing means coupled to the engine for sensing the firing voltage for each cylinder in a cylinder time period and producing a firing signal in response to each firing, processing means operating under stored program control and coupled to said sensing means and responsive to said firing signals for calculating the cylinder time period for each cylinder where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, memory means for storing for each cylinder the cylinder time periods calculated during a plurality of consecutive engine cycles, said processing means including means for calculating for each cylinder the average value of the stored cylinder time periods, said memory means including means for storing said average values for each cylinder, said processing means including means for calculating the overall average of said cylinder average values and for calculating the percentage difference between the average value for each cylinder and the overall average, and display means coupled to said processing means and to said memory means for displaying for each cylinder the percentage difference.
Claim 11
Dependent Claim
230 words
In a system for analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the improvement comprising: sensing means coupled to the engine for sensing the firing voltage for each cylinder in a cylinder time period and producing a firing signal in response to each firing, processing means operating under stored program control and coupled to said sensing means and responsive to said firing signals for calculating the cylinder time period for each cylinder where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, memory means for storing for each cylinder the cylinder time periods calculated during a plurality of consecutive engine cycles, said processing means including means for calculating for each cylinder the average value of the stored cylinder time periods, said memory means including means for storing said average values for each cylinder, said processing means including means for calculating the overall average of said cylinder average values and for calculating the percentage difference between the average value for each cylinder and the overall average, and display means coupled to said processing means and to said memory means for displaying for each cylinder the percentage difference.
Claim 12
Dependent Claim
16 words
The system of claim 9, wherein said memory means stores firing signals for ten engine cycles.
Claim 13
Dependent Claim
44 words
The system of claim 9, wherein said memory means stores firing signals for the most recent predetermined plurality of engine cycles, said processing means calculating running averages of the cylinder time periods, said display means continuously updating the display as the running averages change.
Claim 14
Dependent Claim
25 words
The system of claim 9, wherein the average values of the cylinder time periods for all of the cylinders are displayed in a bar graph.
Claim 15
Dependent Claim
22 words
The system of claim 9, wherein the average values of the cylinder time periods for all of the cylinders are displayed numerically.
Claim 16
Dependent Claim
16 words
The system of claim 9, wherein the overall average of said cylinder average values is displayed.
Claim 17
Independent Claim
135 words
A method of analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the method comprising the steps of: detecting the non-zero firing voltage for each cylinder in a cylinder time period, calculating for each cylinder a value representing its cylinder time period where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, calculating an overall average of the cylinder time period values for all of the cylinders calculating the percentage difference between the cylinder time period value for each cylinder and the overall average, and displaying the percentage difference for each cylinder.
Claim 18
Independent Claim
135 words
A method of analyzing the relative performance of different cylinders of a multiple cylinder internal combustion engine in which a non-zero firing voltage is applied to each cylinder in a predetermined firing order during each engine cycle, the method comprising the steps of: detecting the non-zero firing voltage for each cylinder in a cylinder time period, calculating for each cylinder a value representing its cylinder time period where the cylinder time period of a cylinder is the time between the firing of that cylinder and the firing of the next cylinder in the firing order, calculating an overall average of the cylinder time period values for all of the cylinders calculating the percentage difference between the cylinder time period value for each cylinder and the overall average, and displaying the percentage difference for each cylinder.
Claim 19
Dependent Claim
61 words
The method of claim 15, and further comprising the steps of calculating the cylinder time period for each cylinder, storing for each cylinder the cylinder time periods calculated during a predetermined number of consecutive engine cycles, and calculating for each cylinder the average value of the stored cylinder time periods, said overall average being an average of the cylinder average values.
Claim 20
Dependent Claim
11 words
The method of claim 16, wherein said predetermined number is 10.
Claim 21
Dependent Claim
20 words
The method of claim 15, and further comprising the step of displaying the cylinder time period value for each cylinder.
Claim 22
Dependent Claim
15 words
The method of claim 15, and further comprising the step of displaying the overall average.
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) | 1996-11-01 | 1997-05-03 | 1997-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-01 | 2001-05-03 | 2001-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-01 | 2005-05-03 | 2005-11-02 | $7700.00 | Window Closed / Lapsed |