Patent US3893440A successfully refreshed from Google Patents.
US3893440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic decompression valve to facilitate starting of an internal combustion engine
Assignee: Mcculloch Corp
•
Filing: 1972-10-26
•
Granted: 1975-07-08
•
Expires: 1992-10-26
Abstract
Abstract An automatic decompression valve to facilitate starting of an internal combustion engine is provided having a housing including a gas inlet for receiving compression gas from the cylinder of an internal combustion engine and a gas outlet for venting compression from the cylinder of the internal combustion engine to effect lower compression pressures therein. A valve piston is movable in the housing between a closed position to block communication between the gas inlet and the gas outlet and an open position whereby communication is provided between the gas inlet and the gas outlet. The valve piston has a valve opening reaction surface and a valve closing reaction surface cooperable with pressurized gas to open and close the valve. There is also included a piston position control chamber and a gas flow restrictor which provides restricted fluid communication between the piston position control chamber and pressurized gas entering the gas inlet. Gas pressure in the piston control chamber produces a force on the piston which tends to move the piston to the valve closing position. The gas flow restrictor is also operable to resist the flow of gas out of the piston position control chamber to maintain the piston in the valve open position during initial cranking of the engine and closed during operation of the engine after initial cranking and engine starting. An adjustable stop may be provided to adjust the limits of travel between the valve open and valve closed positions.
Inventors
- 👤 James Linville Dooley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:53
CPC Classifications
F; F01; F01L; F01L13/00; F01L13/08; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
325 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: housing means defining valve cylinder means and including: gas inlet means for receiving compression gas from the cylinder of an internal combustion engine, and gas outlet means for venting compression gas from the cylinder of the internal combustion engine to effect decompression thereof; valve piston means movable in said valve cylinder means between a valve closed position wherein said valve piston means is operable to block communication between said gas inlet means and said outlet means, and a valve open position wherein said valve piston means is operable to render said gas inlet means communicable with said gas outlet means; said valve piston means including a valve opening reaction surface means and valve closing reaction surface means; said valve opening reaction surface means being responsive to pressurized gas entering said gas inlet means for producing a force on said piston means tending to move said piston means to said valve open position; piston position control chamber means; gas flow restriction means, including an orifice, for providing restricted fluid communication between said piston position control chamber means and pressurized gas entering said gas inlet means; said valve closing reaction surface means being responsive to gas pressure in said piston position control chamber means for producing a force on said piston means tending to move said piston means to said valve closed position; said gas flow restriction means being operable to resist flow into said piston position control chamber means of gas entering said gas inlet means so as to maintain said valve piston means in said valve open position during initial cranking of the internal combustion engine; and said gas flow restriction means being further operable to resist flow of gas out of said piston position control chamber means so as to maintain said piston means in said valve closed position during operation of the internal combustion engine after initial cranking.
Claim 2
Dependent Claim
325 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: housing means defining valve cylinder means and including: gas inlet means for receiving compression gas from the cylinder of an internal combustion engine, and gas outlet means for venting compression gas from the cylinder of the internal combustion engine to effect decompression thereof; valve piston means movable in said valve cylinder means between a valve closed position wherein said valve piston means is operable to block communication between said gas inlet means and said outlet means, and a valve open position wherein said valve piston means is operable to render said gas inlet means communicable with said gas outlet means; said valve piston means including a valve opening reaction surface means and valve closing reaction surface means; said valve opening reaction surface means being responsive to pressurized gas entering said gas inlet means for producing a force on said piston means tending to move said piston means to said valve open position; piston position control chamber means; gas flow restriction means, including an orifice, for providing restricted fluid communication between said piston position control chamber means and pressurized gas entering said gas inlet means; said valve closing reaction surface means being responsive to gas pressure in said piston position control chamber means for producing a force on said piston means tending to move said piston means to said valve closed position; said gas flow restriction means being operable to resist flow into said piston position control chamber means of gas entering said gas inlet means so as to maintain said valve piston means in said valve open position during initial cranking of the internal combustion engine; and said gas flow restriction means being further operable to resist flow of gas out of said piston position control chamber means so as to maintain said piston means in said valve closed position during operation of the internal combustion engine after initial cranking.
Claim 3
Dependent Claim
22 words
An automatic decompression valve according to claim 1 wherein said piston means includes a crown portion defining said first reaction surface means.
Claim 4
Dependent Claim
63 words
An automatic decompression valve according to claim 2 wherein said first reaction surface means defined by said crown portion of said piston means includes: a first section continuously communicable with said gas inlet means; and a second section blocked from communication with said gas inlet means with said piston means in said valve closed position, and otherwise communicable with said gas inlet means.
Claim 5
Dependent Claim
82 words
An automatic decompression valve according to claim 3 wherein: said crown portion of said means is cooperable with a valve seat, with said piston means in said valve closed position to block communication between said gas inlet means and said outlet means, and at least a portion of said second section of said first reaction surface means is cooperable with said valve seat to define a low pressure zone of gas vented from said gas inlet means through said gas outlet means.
Claim 6
Dependent Claim
34 words
An automatic decompression valve according to claim 1 wherein said housing means includes adjustable stop means for adjusting the limits of travel of said piston means between said valve open and valve closed positions.
Claim 7
Dependent Claim
34 words
An automatic decompression valve according to claim 1 wherein said piston position control chamber and said valve closing reaction surface means are defined by the walls of a hollow portion of said piston means.
Claim 8
Dependent Claim
22 words
An automatic decompression valve according to claim 6 wherein said piston means includes a crown portion defining said first reaction surface means.
Claim 9
Dependent Claim
63 words
An automatic decompression valve according to claim 7 wherein said first reaction surface means defined by said crown portion of said piston means includes: a first section continuously communicable with said gas inlet means; and a second section blocked from communication with said gas inlet means with said piston means in said valve closed position, and otherwise communicable with said gas inlet means.
Claim 10
Dependent Claim
83 words
An automatic decompression valve according to claim 8 wherein: said crown portion of said piston means is cooperable with a valve seat, with said piston means in said valve closed position to block communication between said gas inlet means and said outlet means, and at least a portion of said second section of said first reaction surface means is cooperable with said valve seat to define a low pressure zone of gas vented from said gas inlet means through said gas outlet means.
Claim 11
Dependent Claim
34 words
An automatic decompression valve according to claim 9 wherein said housing means includes adjustable stop means for adjusting the limits of travel of said piston means between said valve open and valve closed positions.
Claim 12
Dependent Claim
244 words
an automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slidably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and second reaction surface means; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 13
Dependent Claim
244 words
an automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slidably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and second reaction surface means; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 14
Dependent Claim
59 words
The automatic decompression valve of claim 11 wherein an adjusting means is operatively connected to said housing for adjusting a limit of travel of said piston means in said housing to vary the time with respect to the operation of the internal combustion engine, when said valve will restore normal compression to the cylinder of the internal combustion engine.
Claim 15
Dependent Claim
22 words
The automatic decompression valve of claim 12 wherein said adjusting means comprises a screw cap threaded into an end of said housing.
Claim 16
Dependent Claim
49 words
The automatic decompression valve of claim 13 including a shim-seal which is placed between a portion of said screw cap and said housing to effect a fluid-tight seal between said screw cap and said housing and to prevent said screw cap from penetrating said housing beyond a predetermined distance.
Claim 17
Dependent Claim
274 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slideably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and second reaction surface means comprising an orifice in said piston means to place compression gas operating on said first reaction surface means in communication with the gas operating on said second reaction surface means; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 18
Dependent Claim
274 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slideably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and second reaction surface means comprising an orifice in said piston means to place compression gas operating on said first reaction surface means in communication with the gas operating on said second reaction surface means; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 19
Dependent Claim
59 words
The automatic decompression valve of claim 15 wherein an adjusting means is operatively connected to said housing for adjusting a limit of travel of said piston means in said housing to vary the time with respect to the operation of the internal combustion engine, when said valve will restore normal compression to the cylinder of the internal combustion engine.
Claim 20
Dependent Claim
22 words
The automatic decompression valve of claim 16 wherein said adjusting means comprises a screw cap threaded into an end of said housing.
Claim 21
Dependent Claim
49 words
The automatic decompression valve of claim 17 including a shim-seal which is placed between a portion of said screw cap and said housing to effect a fluid-tight seal between said screw cap and said housing and to prevent said screw cap from penetrating said housing beyond a predetermined distance.
Claim 22
Dependent Claim
209 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: elongate housing means having a central bore and communicable with a cylinder of an internal combustion engine, said housing means further comprising: gas inlet means for receiving compression gas from the cylinder: gas outlet means for venting compression gas from the cylinder to effect decompression in the cylinder; piston means slideably disposed in the central bore of said housing means and having a crown portion for selectively blocking communication between said gas inlet means and said gas outlet means; said crown portion having a first reaction surface means having a relatively large area and a second reaction surface means having a relatively small area; said piston means having an orifice in said crown portion to provide means for substantially equalizing the pressure on said first and said second reaction surface means of said crown portion; and means, including said orifice, for creating a force differential across said crown portion produced by gas preSsure acting on said first and second reaction surface means so as to displace said piston means to block communication between said gas inlet means and said gas outlet means and thereby restore compression in the cylinder of the internal combustion engine.
Claim 23
Dependent Claim
209 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: elongate housing means having a central bore and communicable with a cylinder of an internal combustion engine, said housing means further comprising: gas inlet means for receiving compression gas from the cylinder: gas outlet means for venting compression gas from the cylinder to effect decompression in the cylinder; piston means slideably disposed in the central bore of said housing means and having a crown portion for selectively blocking communication between said gas inlet means and said gas outlet means; said crown portion having a first reaction surface means having a relatively large area and a second reaction surface means having a relatively small area; said piston means having an orifice in said crown portion to provide means for substantially equalizing the pressure on said first and said second reaction surface means of said crown portion; and means, including said orifice, for creating a force differential across said crown portion produced by gas preSsure acting on said first and second reaction surface means so as to displace said piston means to block communication between said gas inlet means and said gas outlet means and thereby restore compression in the cylinder of the internal combustion engine.
Claim 24
Dependent Claim
59 words
The automatic decompression valve of claim 19 wherein an adjusting means is operatively connected to said housing for adjusting a limit of travel of said piston means in said housing to vary the time with respect to the operation of the internal combustion engine, when said valve will restore normal compression to the cylinder of the internal combustion engine.
Claim 25
Dependent Claim
22 words
The automatic decompression valve of claim 20 wherein said adjusting means comprises a screw cap threaded into an end of said housing.
Claim 26
Dependent Claim
49 words
The automatic decompression valve of claim 21 including a shim-seal which is placed between a portion of said screw cap and said housing to effect a fluid-tight seal between said screw cap and said housing and to prevent said screw cap from penetrating said housing beyond a predetermined distance.
Claim 27
Dependent Claim
307 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slideably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and said second reaction surface means comprising an orifice in said piston means to place compression gas operating on said first reaction surface means in communication with the gas operating on said second reaction surface means and valve means in said orifice for blocking said orifice during an exhaust stroke of the internal combustion engine and opening said orifice during a compression stroke of the internal combustion engine; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 28
Dependent Claim
307 words
An automatic decompression valve to facilitate starting of an internal combustion engine, said valve comprising: an elongate housing having a central bore and communicable with a cylinder of an internal combustion engine; piston means slideably disposed in the bore of said housing for selectively moving between an open and closed position with respect to the bore; actuation means for automatically displacing said piston means from a position to open the bore during cranking of the internal combustion engine to a position to close the bore after the internal combustion engine has started; said actuation means comprising: a first reaction surface means on said piston means operably responsive to a first compression stroke of the internal combustion engine for displacing said piston means to the position to open the bore to provide decompression in the cylinder of the internal combustion engine; a second reaction surface means on said piston means responsive to gas pressure produced by compression pressure on said first reaction surface means; means for substantially equalizing the pressure on said first and said second reaction surface means comprising an orifice in said piston means to place compression gas operating on said first reaction surface means in communication with the gas operating on said second reaction surface means and valve means in said orifice for blocking said orifice during an exhaust stroke of the internal combustion engine and opening said orifice during a compression stroke of the internal combustion engine; and said second reaction surface means having a greater area than the area of said first reaction surface means to effect a differential force on said piston means when the pressure is substantially equalized on said first and second reaction surface means to aid in displacing said piston means to a position to close the bore to restore compression in the cylinder of the internal combustion engine.
Claim 29
Dependent Claim
23 words
The automatic decompression valve of claim 23 wherein said valve means comprises a spring biased ball seated against a mouth of said orifice.
Claim 30
Dependent Claim
59 words
The automatic decompression valve of claim 23 wherein an adjusting means is operatively connected to said housing for adjusting a limit of travel of said piston means in said housing to vary the time with respect to the operation of the internal combustion engine when said valve will restore normal compression to the cylinder of the internal combustion engine.
Claim 31
Dependent Claim
22 words
The automatic decompression valve of claim 25 wherein said adjusting means comprises a screw cap threaded into an end of said housing.
Claim 32
Dependent Claim
49 words
The automatic decompression valve of claim 26 including a shim-seal which is placed between a portion of said screw cap and said housing to effect a fluid-tight seal between said screw cap and said housing and to prevent said screw cap from penetrating said housing beyond a predetermineD distance.
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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |