Patent US3889528A successfully refreshed from Google Patents.
US3889528A
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Method and apparatus for determining top dead center in internal combustion engines
Assignee: SCANS ASSOCIATES Inc
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Filing: 1974-04-18
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Granted: 1975-06-17
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Expires: 1994-04-18
Abstract
Abstract The specification discloses a novel method and apparatus for determining in an uncomparably more precise manner than was possible heretofore the top dead center in one selected cylinder of an internal combustion engine, to provide a reference point to which all of the ensuing adjustments in tuning the engine are referred. In accordance with the invention, the determination of the top dead center in the selected cylinder of an internal combustion engine is made not on the basis of movement of the piston, or pistons, or position of a journal, determination of which is being made, but on the basis of movement of the piston or position of the journal in another cylinder having set relationship to the position of the piston or journal in the selected cylinder. Generally, the relation is such that movement of the piston along the straight line is very small near the top dead center compared to the angle of crankshaft rotation, and determination of the top dead center made on the basis of such movement would be only approximate and unreliable. In accordance with the invention, determination of the top dead center is made on the basis of movement of the piston in another cylinder in the position at or near the mid-stroke of the piston when the movement of the piston for the same angle of crankshaft rotation is the largest and when such movement referred to the position of the piston in the selected cylinder enables marking position of the top dead center of the piston in such selected cylinder with much greater precision. Generally, the above relationship may be compared to sine and cosine relationship. At or near the top dead center, the movement of the piston is proportional to the cosine of the angle of crankshaft rotation, and at or near the mid-stroke of the piston-proportional to the sine of such angle. Thus, determination of the top dead center in one selected cylinder resolves itself to determination of the position at or near the midstroke of a piston having set relation to the position of piston in a selected cylinder, and having found that position, marking the position of the piston in a selected cylinder as being precisely at the top dead center. The specification also discloses the method and apparatus for determining the top dead center of the selected piston by balancing two adjacent pistons, one moving downwardly and one moving upwardly, both mechanically and electrically, as well as finding such positions by setting respective journals of the crankshaft accordingly.
Inventors
- 👤 Henry W Grikscheit
- 👤 Iii Vernon G Converse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:29
CPC Classifications
G; G01; G01M; G01M15/00; G01M15/04; G01M15/06; G01B; G01B5/00; G01B5/003; Y; Y10; Y10S; Y10S33/00; Y10S33/15
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
269 words
A method for determining the top dead center position of a selected piston in an internal combustion engine having at least three cylinders based on the position of one other piston other than said selected piston, sAid method including positioning said other selected piston at the uppermost point in its stroke, measuring the distance from the top of said other piston''s respective cylinder bore to the head of said one other piston, positioning said one other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining from the type of internal combustion engine being operated upon, the angle which the journal corresponding to said one other piston must be set at, measured from the center line plane of the engine''s cylinder bore, such that the selected piston will be at its top dead center position, determining from said angle, said crankshaft throw, and the length of said connecting rod corresponding to said one other piston, the distance measured from the top of the cylinder bore of said one other cylinder which said one other piston must be placed at to insure said selected piston is at its top dead center position, placing the head of said one other piston at said distance measured from the top of the cylinder bore, and marking the position of said selected piston as being in the position of top dead center.
Claim 2
Independent Claim
269 words
A method for determining the top dead center position of a selected piston in an internal combustion engine having at least three cylinders based on the position of one other piston other than said selected piston, sAid method including positioning said other selected piston at the uppermost point in its stroke, measuring the distance from the top of said other piston''s respective cylinder bore to the head of said one other piston, positioning said one other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining from the type of internal combustion engine being operated upon, the angle which the journal corresponding to said one other piston must be set at, measured from the center line plane of the engine''s cylinder bore, such that the selected piston will be at its top dead center position, determining from said angle, said crankshaft throw, and the length of said connecting rod corresponding to said one other piston, the distance measured from the top of the cylinder bore of said one other cylinder which said one other piston must be placed at to insure said selected piston is at its top dead center position, placing the head of said one other piston at said distance measured from the top of the cylinder bore, and marking the position of said selected piston as being in the position of top dead center.
Claim 3
Independent Claim
186 words
A method for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft based on the position of one other piston other than the number one piston which would be at its mid-crank position when said number one piston would be at its top dead center position, said method including positioning said other piston at the uppermost point in its stroke, measuring the distance from the top of said other pistons respective cylinder bore to the head of said other piston, positioning said other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining from said measurements the mid-crank position of said other piston, placing the head of said other piston at said mid-crank position, and marking the position of the number one piston as being in the position of top dead center.
Claim 4
Independent Claim
186 words
A method for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft based on the position of one other piston other than the number one piston which would be at its mid-crank position when said number one piston would be at its top dead center position, said method including positioning said other piston at the uppermost point in its stroke, measuring the distance from the top of said other pistons respective cylinder bore to the head of said other piston, positioning said other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining from said measurements the mid-crank position of said other piston, placing the head of said other piston at said mid-crank position, and marking the position of the number one piston as being in the position of top dead center.
Claim 5
Independent Claim
175 words
A method for determining the top dead center position of the number one piston in a six-cylinder in-line internal combustion engine based on the position of one other piston which would be at its two-thirds crank position when said number one piston would be at its top dead center position, said method including positioning said other piston at the uppermost point in its stroke, measuring the distance from the top of said other pistons respective cylinder bore to the head of said one other piston, positioning said other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining the two-thirds crank position of said other piston, placing said other piston at its two-thirds crank position, and marking the position of the number one piston as being in the position of top dead center.
Claim 6
Independent Claim
175 words
A method for determining the top dead center position of the number one piston in a six-cylinder in-line internal combustion engine based on the position of one other piston which would be at its two-thirds crank position when said number one piston would be at its top dead center position, said method including positioning said other piston at the uppermost point in its stroke, measuring the distance from the top of said other pistons respective cylinder bore to the head of said one other piston, positioning said other piston at the lowermost position in its stroke, again measuring the distance from the top of said cylinder bore to the head of said one other piston, determining from said measurements the stroke of said one other piston, and thereby determining the throw of the crankshaft of said internal combustion engine, determining the two-thirds crank position of said other piston, placing said other piston at its two-thirds crank position, and marking the position of the number one piston as being in the position of top dead center.
Claim 7
Independent Claim
79 words
The method of determining in a V-8 internal combustion engine the position of the top dead center of the piston in number one cylinder, which method includes determining the mid-crank position of the piston adjacent the number one piston, placing said adjacent piston in its mid-crank position, and marking the position of the piston of number one cylinder on the basis of the position of the piston adjacent the number one cylinder as being at the top dead center.
Claim 8
Independent Claim
79 words
The method of determining in a V-8 internal combustion engine the position of the top dead center of the piston in number one cylinder, which method includes determining the mid-crank position of the piston adjacent the number one piston, placing said adjacent piston in its mid-crank position, and marking the position of the piston of number one cylinder on the basis of the position of the piston adjacent the number one cylinder as being at the top dead center.
Claim 9
Independent Claim
78 words
The Method of determining in a six-cylinder in-line internal combustion engine having a star-shaped crankshaft, the position of the top dead center of the piston in number one cylinder, which method includes determining the two-thirds crank position of the piston in the cylinder adjacent to the number one cylinder, placing said adjacent piston in its two-thirds crank position, and marking the position of the piston in number one cylinder as being at the position of top dead center.
Claim 10
Independent Claim
78 words
The Method of determining in a six-cylinder in-line internal combustion engine having a star-shaped crankshaft, the position of the top dead center of the piston in number one cylinder, which method includes determining the two-thirds crank position of the piston in the cylinder adjacent to the number one cylinder, placing said adjacent piston in its two-thirds crank position, and marking the position of the piston in number one cylinder as being at the position of top dead center.
Claim 11
Independent Claim
67 words
The method of determining in a V-8 internal combustion engine having a square crankshaft, the position of the top dead center of the piston in the number one cylinder, which method comprises determining the mid-crank position of the number three piston, setting the number three piston at its mid-crank position, and thereupon marking the position of the number one piston as being at its top dead center.
Claim 12
Independent Claim
67 words
The method of determining in a V-8 internal combustion engine having a square crankshaft, the position of the top dead center of the piston in the number one cylinder, which method comprises determining the mid-crank position of the number three piston, setting the number three piston at its mid-crank position, and thereupon marking the position of the number one piston as being at its top dead center.
Claim 13
Independent Claim
68 words
The method of determining in a six-cylinder in-line internal combustion engine having a star-shaped crankshaft the position of the top dead center of the piston in number one cylinder, said method including determining the two-thirds crank position of the number two piston, placing the number two piston at said two-thirds crank position, and then marking the position of the number one piston as being at top dead center.
Claim 14
Independent Claim
68 words
The method of determining in a six-cylinder in-line internal combustion engine having a star-shaped crankshaft the position of the top dead center of the piston in number one cylinder, said method including determining the two-thirds crank position of the number two piston, placing the number two piston at said two-thirds crank position, and then marking the position of the number one piston as being at top dead center.
Claim 15
Independent Claim
63 words
The method of determining in a V-6 internal combustion engine the position of the top dead center of the piston in number one cylinder, said method comprising determining the two-thirds crank position of the number three piston, setting said number three piston at said two-thirds crank position, and then marking the position of the number one piston as being at top dead center.
Claim 16
Independent Claim
63 words
The method of determining in a V-6 internal combustion engine the position of the top dead center of the piston in number one cylinder, said method comprising determining the two-thirds crank position of the number three piston, setting said number three piston at said two-thirds crank position, and then marking the position of the number one piston as being at top dead center.
Claim 17
Independent Claim
74 words
The method of determining in a four-cylinder internal combustion engine having a square crankshaft, the position of the top dead center of the piston in number one cylinder, said method including determining the mid-crank position of the piston in the cylinder adjacent number one cylinder, setting said adjacent piston at said mid-crank position, and thereupon marking the position of the piston in number one cylinder, as being in the position of top dead center.
Claim 18
Independent Claim
74 words
The method of determining in a four-cylinder internal combustion engine having a square crankshaft, the position of the top dead center of the piston in number one cylinder, said method including determining the mid-crank position of the piston in the cylinder adjacent number one cylinder, setting said adjacent piston at said mid-crank position, and thereupon marking the position of the piston in number one cylinder, as being in the position of top dead center.
Claim 19
Dependent Claim
285 words
Apparatus for determining the top dead center position of a selected piston in an internal combustion engine having at least three cylinders based on the position of one other piston other than said selected piston, said apparatus including means to position said other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said one other piston, means to position said one other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said one other piston, means to determine from said measurements the stroke of said one other piston, and thereby determine the throw of the crankshaft of said internal combustion engine, means to determine from the type of internal combustion engine being tested, the angle which the journal corresponding to said one other piston must be set at, measured from the center line plane of the engine''s cylinder bore, such that the selected piston will be at its top dead center position, means to determine from said angle, said crankshaft throw and the length of said connecting rod corresponding to said one other piston, the distance measured from the top of the cylinder bore of said one other cylinder which said one other piston must be placed at to insure that said selected piston is at its top dead center position, means to place the head of said one other piston at said distance measured from the top of said cylinder bore, and means to mark the position of said selected piston as being in the position of top dead center.
Claim 20
Dependent Claim
285 words
Apparatus for determining the top dead center position of a selected piston in an internal combustion engine having at least three cylinders based on the position of one other piston other than said selected piston, said apparatus including means to position said other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said one other piston, means to position said one other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said one other piston, means to determine from said measurements the stroke of said one other piston, and thereby determine the throw of the crankshaft of said internal combustion engine, means to determine from the type of internal combustion engine being tested, the angle which the journal corresponding to said one other piston must be set at, measured from the center line plane of the engine''s cylinder bore, such that the selected piston will be at its top dead center position, means to determine from said angle, said crankshaft throw and the length of said connecting rod corresponding to said one other piston, the distance measured from the top of the cylinder bore of said one other cylinder which said one other piston must be placed at to insure that said selected piston is at its top dead center position, means to place the head of said one other piston at said distance measured from the top of said cylinder bore, and means to mark the position of said selected piston as being in the position of top dead center.
Claim 21
Dependent Claim
67 words
The apparatus defined in claim 10, wherein said measuring means comprise a structural frame member adapted to be placed on and sealingly mounted over said other cylinder, thereby enclosing Said other cylinder as well as a suitable working-space there above, said frame member having an adaptor collar assembly slidably mounted therein directly above said one other piston, and adapted to measure the respective positions of said piston.
Claim 22
Dependent Claim
118 words
The apparatus defined in claim 11, wherein said adaptor collar assembly comprises a member with an upper and lower end, said upper end being of enlarged cross-section, said member having an axially extending passageway there through, a linear transformer adapted to give an electrical output signal directly proportional to the linear displacement of its moveable probe adjustably mounted at the upper end of said hollow member in such a manner that said probe extends into said passageway, a shaft slidably mounted in said passageway below and communicating with said probe, a bushing fixedly mounted on the end of said shaft, means to provide tension on said bushing, and means to contact said piston fixedly mounted to said bushing.
Claim 23
Dependent Claim
26 words
The apparatus defined in claim 12, wherein said tension providing means are in the form of a spring around said bushing pushing outwardly from said collar.
Claim 24
Dependent Claim
48 words
The apparatus defined in claim 13, wherein said piston contacting means include a crows-foot device with three radially downwardly extending legs, and contact pads mounted on said legs at the end thereof to guarantee that said crows-foot device will be perpendicular with the centerline of said linear transformer.
Claim 25
Dependent Claim
66 words
The apparatus defined in claim 14, and including means to lower and hold said adaptor collar assembly in an extended position so as to place said piston contacting means in close proximity to the piston being measured, means to retract said assembly when the measurements are done, and means to utilize the output signal of said linear transformer to indicate the various positions of said piston.
Claim 26
Dependent Claim
183 words
The apparatus defined in claim 15, and including an exciter-demodulator to drive said linear transformer to produce a desired voltage output range, a memory circuit adapted to receive a signal from said exciter-demodulator when said other piston is at its uppermost position, an adder-subtracter adapted to receive a signal from said exciter demodulator when said other piston is at other than its uppermost position, a voltage follower to match the impedence of the output signal of said linear transformer to the impedence of said adder-subtracter, means to transfer the signal from the exciter-demodulator to said memory circuit when said one other piston is at its lowermost position, and a mini-computer adapted to receive information from said memory circuit and to compute the distance measured from the top of the cylinder bore of said one other cylinder which said one other piston must be placed at to insure said selected piston is at its top dead center position, means to indicate the result from said mini-computer, and means to set said one other piston at said distance from the top of its cylinder bore.
Claim 27
Dependent Claim
17 words
The apparatus defined in claim 16, wherein the indicating means is in the form of a voltmeter.
Claim 28
Dependent Claim
18 words
The apparatus defined in claim 16 wherein the indicating means is in the form of a digital voltmeter.
Claim 29
Dependent Claim
40 words
The apparatus defined in claim 15, wherein the lowering means include a vacuum operated cylinder, and a vacuum pump connected to said vacuum operated cylinder in such a manner as to cause upward movement of the piston of said cylinder.
Claim 30
Dependent Claim
60 words
The apparatus defined in claim 15, wherein said assembly retracting means include a vacuum operated cylinder with its piston rod fixedly mounted to said frame member, said cylinder operatively connected to said collar, and a vacuum pump connected in such a manner as to cause the cylinder to move to its fully extended position and remain there until used again.
Claim 31
Dependent Claim
36 words
The apparatus defined in claim 15, wherein the lowering and retracting of said collar is performed by a single dual action vacuum operated cylinder connected to said vacuum pump, and controlled by a dual action valve.
Claim 32
Independent Claim
200 words
An apparatus for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft based on the position of one other piston other than the number one piston which would be at its mid-crank position when said number one piston would be at its top dead center position, said apparatus including means to position said one other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said other piston, means to position said other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said one other piston, means to determine from said measurements the stroke of said one other piston, and thereby determine the throw of the crankshaft of said internal combustion engine, means to determine from said measurements the mid-crank position of said other piston, means to position said other piston at said mid-crank position, and means to mark the position of the number one cylinder as being in the position of top dead center.
Claim 33
Independent Claim
200 words
An apparatus for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft based on the position of one other piston other than the number one piston which would be at its mid-crank position when said number one piston would be at its top dead center position, said apparatus including means to position said one other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said other piston, means to position said other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said one other piston, means to determine from said measurements the stroke of said one other piston, and thereby determine the throw of the crankshaft of said internal combustion engine, means to determine from said measurements the mid-crank position of said other piston, means to position said other piston at said mid-crank position, and means to mark the position of the number one cylinder as being in the position of top dead center.
Claim 34
Independent Claim
192 words
An apparatus for determining the top dead center position of the number one piston in a six-cylinder in-line internal combustion engine by an operation on the position of one other piston which would be at its two-thirds crank position when said number one piston would be at its top dead center position, said apparatus including means to position said other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said other piston, means to position said other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said other piston, means to determine from said measurements the stroke of said one other piston, and thereby to determine the throw of the crankshaft of said internal combustion engine, means to determine the two-thirds crank position of said one other piston, means to position said other piston at its two-thirds crank position, and means to mark the position of the number one piston as being at its top dead center position.
Claim 35
Independent Claim
192 words
An apparatus for determining the top dead center position of the number one piston in a six-cylinder in-line internal combustion engine by an operation on the position of one other piston which would be at its two-thirds crank position when said number one piston would be at its top dead center position, said apparatus including means to position said other piston at the uppermost point in its stroke, means to measure the distance from the top of said other pistons respective cylinder bore to the head of said other piston, means to position said other piston at the lowermost position in its stroke, means to again measure the distance from the top of said cylinder bore to the head of said other piston, means to determine from said measurements the stroke of said one other piston, and thereby to determine the throw of the crankshaft of said internal combustion engine, means to determine the two-thirds crank position of said one other piston, means to position said other piston at its two-thirds crank position, and means to mark the position of the number one piston as being at its top dead center position.
Claim 36
Independent Claim
71 words
An apparatus for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft, said apparatus including means to determine the mid-crank position of the number three piston, means to position said number three piston at said mid-crank position, and means to mark the position of the piston of number one cylinder as being in the position of top dead center.
Claim 37
Independent Claim
71 words
An apparatus for determining the top dead center position of the number one piston in a V-8 internal combustion engine having a square crankshaft, said apparatus including means to determine the mid-crank position of the number three piston, means to position said number three piston at said mid-crank position, and means to mark the position of the piston of number one cylinder as being in the position of top dead center.
Claim 38
Independent Claim
71 words
An apparatus for determining the top dead center position of the number one piston in an in-line six cylinder internal combustion engine, said apparatus including means to determine the two-thirds crank position of the number two piston, means to position the number two piston at said two-thirds crank position, and means to mark the position of the piston of number one cylinder as being in the position of top dead center.
Claim 39
Independent Claim
71 words
An apparatus for determining the top dead center position of the number one piston in an in-line six cylinder internal combustion engine, said apparatus including means to determine the two-thirds crank position of the number two piston, means to position the number two piston at said two-thirds crank position, and means to mark the position of the piston of number one cylinder as being in the position of top dead center.
Claim 40
Independent Claim
191 words
An apparatus for determining the top dead center position of the number one piston of an internal combustion engine of the type having at least three pistons adapted to reciprocate within cylinders in said engine, and being of the V or in-line type, said apparatus including a hollow frame member having parallel upper and lower edges, said upper edges adapted to contact the pan rail of said internal combustion engine, and said lower edges adapted to support said frame member, a vertically moveable platform parallel to said pan rail contacting edges contained inside said hollow frame member and adapted to contact two journals of said internal combustion engine, said two journals being the two journals of the engine whose corresponding pistons would be in a juxtaposition when the number one piston would be at its top dead center position, means To raise and lower said vertically moveable platform into and out of engagement with said two journals, and means to mark the position of said number one journal as being at top dead center when said two journals are in contact with said vertically moveable platform, and therefore are in juxtaposition.
Claim 41
Independent Claim
191 words
An apparatus for determining the top dead center position of the number one piston of an internal combustion engine of the type having at least three pistons adapted to reciprocate within cylinders in said engine, and being of the V or in-line type, said apparatus including a hollow frame member having parallel upper and lower edges, said upper edges adapted to contact the pan rail of said internal combustion engine, and said lower edges adapted to support said frame member, a vertically moveable platform parallel to said pan rail contacting edges contained inside said hollow frame member and adapted to contact two journals of said internal combustion engine, said two journals being the two journals of the engine whose corresponding pistons would be in a juxtaposition when the number one piston would be at its top dead center position, means To raise and lower said vertically moveable platform into and out of engagement with said two journals, and means to mark the position of said number one journal as being at top dead center when said two journals are in contact with said vertically moveable platform, and therefore are in juxtaposition.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |