U.S. patent number 3,710,772 [Application Number 05/061,933] was granted by the patent office on 1973-01-16 for anti-fouling spark ignition devices.
This patent grant is currently assigned to Eldapat General, Inc.. Invention is credited to Richard C. Warner.
United States Patent |
3,710,772 |
Warner |
January 16, 1973 |
ANTI-FOULING SPARK IGNITION DEVICES
Abstract
An axially elongated member is provided with an antechamber at
one end thereof for receivably engaging the firing end of a spark
ignition device. The axially elongated member includes a
diverging-converging exit nozzle in its other end and a narrow bore
or port extending between and connecting the antechamber with the
exit nozzle. The nozzle's exit aperture is formed in the end face
of the member and thus defines an annular baffle means axially
displaced from the point where the narrow bore opens into the exit
nozzle. Because of its diverging-converging construction the
interior recess of the nozzle is enlarged with respect to the
diameter of its exit aperture which latter, in turn, is enlarged
with respect to the diameter of the narrow bore or port. The axial
member further includes means for preventing a fluid flowing along
a wall surface perpendicular to the axis thereof from flowing over
the end face of its other end and entering the enlarged interior
recess of the exit nozzle.
Inventors: |
Warner; Richard C. (Morris
Plains, NJ) |
Assignee: |
Eldapat General, Inc. (Morris
Plains, NJ)
|
Family
ID: |
22039091 |
Appl.
No.: |
05/061,933 |
Filed: |
August 7, 1970 |
Current U.S.
Class: |
123/169R;
123/169P; 123/169PA; 313/138 |
Current CPC
Class: |
H01T
13/54 (20130101) |
Current International
Class: |
H01T
13/00 (20060101); H01T 13/54 (20060101); H01t
013/02 () |
Field of
Search: |
;123/169R,169CL,169CM,169CA,169CB,169DW,169EL,169EC,169C,169E,169G
;313/138 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Goodridge; Laurence M.
Claims
I claim:
1. Apparatus for use with a spark ignition device including an
insulting core body and a center electrode carried by said core
body and protruding therefrom at one end thereof, comprising:
an axially extending member adapted for cooperative engagement with
said spark ignition device; said member including an interior
cavity for receivably enclosing said protruding center electrode,
an exit mouth axially displaced from said cavity, and a connecting
port extending between said cavity and said exit mouth, one end of
said connecting port communicating with said interior cavity and
the other end of said connecting port communicating with said exit
mouth;
said exit mouth having an exit aperture axially displaced from said
other end of said connecting port, the diameter of said exit
aperture being greater than the diameter of said port, said exit
mouth forming a diverging-converging interior recess having a major
diameter axially disposed between said other end of said connecting
port and said exit aperture, said major diameter of said
diverging-converging recess being greater than the diameter of said
exit aperture.
2. The apparatus of claim 1 wherein said axially extending member
includes a remotely disposed end face defining its axial extremity,
said exit aperture being located in said end face.
3. The apparatus of claim 1 wherein said major diameter of said
converging-diverging recess is axially located relatively nearer to
said exit aperture than to said other end of said connecting
port.
4. The apparatus of claim 2 wherein said end face is substantially
flat and defines an annular radially extending baffle axially
displaced from said other end of said connecting port and
surrounding said exit aperture.
5. The apparatus of claim 2 wherein said end face of said axially
extending member is adapted for cooperation with the inner wall
surface of an internal combustion engine and includes means for
preventing a fluid flowing along said inner wall surface from
flowing over said end face and entering the interior recess of said
exit mouth.
6. The apparatus of claim 5 wherein said last mentioned means
includes an annular groove recessed into the exterior surface of
said axially extending member near said end face, said annular
groove being located adjacent to said inner wall surface when said
member is in cooperative engagement therewith.
7. The apparatus of claim 6 wherein said end face is flush with
respect to said inner wall surface.
8. The apparatus of claim 6 wherein said end face extends beyond
said inner wall surface.
9. The apparatus of claim 1 wherein said insulating core body is
positioned within an outer shell member surrounding said protruding
electrode, and said interior cavity is adapted to threadedly
receive said outer shell member in sealing engagement
therewithin.
10. The apparatus of claim 1 wherein said insulated core body is
positioned within an outer shell member integrally joined with said
axially extending member.
11. The apparatus of claim 1 wherein said axially extending member
comprises the wall of an internal combustion engine.
12. The apparatus of claim 5 wherein said axially extending member
includes an externally threaded portion adjacent said end face for
engaging an internally threaded spark plug receiving port
communicating with said inner wall surface.
13. The apparatus of claim 1 wherein said diverging-converging
interior recess forming said exit mouth comprises a pair of
inverted frusto-conical chambers having an imaginary common base
the diameter of which conforms to said major diameter, said common
base being axially located nearer to said exit aperture than to
said other end of said connecting port.
14. Anti-fouling means for use with a spark plug device,
comprising: an outer shell member having an antechamber at one end
and an exit nozzle at the other end, narrow passageway means for
communicating the inner end of said antechamber with the inner end
of said exit nozzle, said exit nozzle having means for preventing
fluid such as oil from entering the narrow passageway means and
collecting in said antechamber when said outer shell member is
maintained in a substantially horizontal position, said last
mentioned means including an annular lip formed at the outer
extremity of said exit nozzle, said annular lip defining an exit
aperture of smaller diameter than the inner portion of said nozzle,
said narrow passageway mans being of smaller diameter than said
aperture whereby any oil tending to collect within the inner
portions of said nozzle will flow outwardly over said lip before
backflowing through said passageway into said antechamber.
15. The apparatus of claim 14 wherein said other end of said outer
shell member is adapted for cooperation with the inner wall surface
of an engine, and said last mentioned means further comprises means
exteriorly formed with respect to said exit nozzle in the vicinity
of said wall surface for preventing said fluid as may be flowing
along said wall surface from entering said exit nozzle.
16. The apparatus of claim 15 in which said means exteriorily
formed with respect to said exit nozzle comprises an annular groove
surrounding said exit nozzle.
17. The apparatus of claim 16 in which said annular groove defines
an outwardly flared extremity at said other end of said outer shell
member, said outwardly flared extremity terminating in a
substantially flat end face, said exit nozzle having its exit
aperture located in the plane of said flat end face.
18. The apparatus of claim 14 wherein said antechamber is adapted
to receivably engage the firing end of said spark plug device.
Description
The present invention relates generally to spark ignition devices
and more particularly to an improved anti-fouling spark plug for
use in internal combustion engines or the like. The term
anti-fouling spark plug as applied to the present invention refers
to a spark plug having means associated therewith for preventing
oil, carbon, and other debris from lodging in or near the electrode
gap of the plug and thus preventing such foreign matter from
interfering with the proper operation of the plug.
Anti-fouling spark plugs have been proposed heretofore wherein the
spaced electrodes forming the sparking gap are recessed in an
antechamber formed in an axially protruding extension of the spark
plug's shell. The chamber which completely encloses the sparking
electrodes at one of its axial extremities, communicates with a
narrow apertured bore or port at its other opposed extremity. This
port or bore communicates, in turn, with the principle combustion
chamber or cylinder of the internal combustion engine with which
the plug is used. By situating the electrodes at one end of the
antechamber and providing a narrow apertured bore at the other
opposed end of the antechamber the spark plug's electrodes are
normally shielded or baffled from the oil and debris swirling about
in the engine's combustion chamber. However, the atomized fuel/air
mixture can easily penetrate the narrow bore opening to the
antechamber and may readily be ignited when the spark plug fires.
The resulting flames are then expelled through the narrow bore
because of the rapid pressure increase in the antechamber to ignite
the main mixture in the principle combustion chamber.
Although the prior art anti-fouling spark plugs have generally
operated satisfactorily with certain types of internal combustion
engines, they have been found to suffer from the major disadvantage
of being extremely critical with regard to their location. In a
great many modern internal combustion engines, particularly those
used in automobiles, trucks, and other vehicles, the spark plug
receiving ports in the engine wall are positioned so that the
plug's firing end extends into the combustion chamber below the
cylinder's intake and exhaust valves. In addition, when the plugs
are screwed into their corresponding ports, they usually assume a
slightly tilted attitude with respect to a local horizontal
direction, that is, with the firing end of the plug being slightly
raised with reference to its terminal or rearward end. Such engine
arrangements are generally referred to as being of the overhead
valve type.
It is well known that droplets of lubricating oil occassionly seep
or escape through the valve stem seals in such engines, especially
when the latter have been in use for a considerable time and are
beginning to show signs of wear. These droplets of oil tend to flow
downwardly along the walls of the combustion chamber under the
influence of gravity until eventually they reach the exposed
electrodes of the plugs, causing fouling and improper firing of
same. Even when anti-fouling plugs are employed, the oil manages to
flow into and through the narrow bore or port of the plug's
antechamber and because of the slight upward cant of the plug,
readily pools or collects around the electrodes thus fouling the
plug nonetheless. Only when the anti-fouling plug is mounted in an
engine where the orientation of the spark plug receiving ports
requires the firing end of the spark plug to be lower than the
plug's rearward or terminal end will gravity help to keep oil from
pooling at the electrodes and eventually causing improper firing
thereof. It is readily apparent therefore that such prior art
anti-fouling plugs are in fact, totally ineffectual in preventing
fouling due to oil pollution when used in engines requiring a
static mounting position for the plugs that is more or less
horizontal.
Accordingly, it is the primary object of the present invention to
provide an improved spark plug means having unique features of
construction for effectively preventing fouling of the plug's
electrodes by foreign matter or debris.
It is another object of the present invention to provide an
improved spark plug means that is particularly resistant to the
fouling effects of oil.
It is yet another object of the present invention to provide an
improved anti-fouling spark plug means that can be mounted in a
substantially horizontal static operating position in an internal
combustion engine, yet will not be affected by the polluting
effects of oil or other engine debris.
To the accomplishment of these and other objects and advantages,
the improved anti-fouling spark plug means of the present invention
comprises an axially extending outer shell member including an
interior cavity adapted for receiving therewithin a sparking
discharge means. The outer shell member further comprises a
terminal portion adapted to extend into the combustion chamber or
cylinder of an internal combustion engine and has a
diverging-converging recess formed interiorly thereof to define an
exit nozzle or chamber. The cavity and the chamber are connected by
a narrow axial bore or port having a diameter smaller than the
mouth or exit aperture of the chamber which aperture, in turn, has
a diameter smaller than the major diameter of the chamber itself. A
second grooved annulus formed exteriorly on the outer shell
member's terminal portion near the shell member's axial extremity
completely surrounds the exit aperture of the nozzle.
Additional features and advantages of the present invention will be
made more apparent from a study of the following detailed
description of the invention in connection with the accompanying
drawings wherein:
FIG. 1 is a front view of the improved spark plug of the present
invention;
FIG. 2 is a sectional view in side elevation of the spark plug of
FIG. 1 taken along line 2--2;
FIG. 3 is an enlarged detail view of a fragmentary portion of FIG.
2;
FIG. 4 is a side view partly in section of an alternate preferred
form of the present invention, and;
FIG. 5 is a side view partly in section of yet another
alternatively preferred form of the present invention.
Turning now to FIGS. 1 and 2, there is shown one preferred form of
the improved spark plug according to the present invention
comprising an insulating core member 10 coaxially received within
an outer shell member 12. The core member 10 which may be of
porcelain, ceramic or other such heat resistant non-conductive
material, has longitudinally disposed therein an elongated central
electrode 14. One end of electrode 14 is integrally connected to a
conductive terminal post 16 while its opposed other end protrudes
slightly from the tapered end portion of the insulating core member
as shown at reference numberal 18. The core member is clamped in or
otherwise fixedly secured to the outer shell member with a pair of
sealing gaskets or the like 20 and 22 being disposed therebetween.
It will be appreciated that any conventional method of clamping the
core member within its outer shell may be employed, and since this
aspect of construction forms no part of the present invention, it
need not be further discussed herein.
As viewed in FIG. 2, outer shell member 12 has formed exteriorly
thereon near its left most end, a radially flanged portion 24
having suitable hexagonally faced edges (FIG. 1) capable of
receiving a spanner wrench or similar tool. The right-most or
extreme axial end of the outer shell member terminates in a portion
of reduced size having suitable threads 26 thereon for
cooperatively engaging the spark plug receiving port of an internal
combustion engine. As will be explained in more detail below, the
extremity of this reduced-size threaded end portion of the outer
shell member is necked-down to form a substantially V-shaped
grooved annulus 28 concentrically surrounding the mouth or firing
end of the spark plug.
The outer shell member carries a pair of opposed ground electrodes
30, 32 which extend laterally into a cavity 34 formed within the
interior of the outer shell member and surrounding the protruding
end 18 of the central electrode 14. Each ground electrode 30, 32 is
radially spaced from the common center electrode 14 so as to form a
pair of sparking gaps in conjunction therewith. As will occur to
those skilled in the art, and depending upon individual
requirements, a single ground electrode (not shown) extending into
cavity 34 in axially spaced relation to central electrode 14 may be
used to form a single gap instead of the two formed when the dual
electrodes 30, 32 are employed. As shown, cavity 34 opens into
another cavity 36 interiorly of outer shell/member 12 and the two
cavities 34 and 36 together define an antechamber therein
completely enveloping the sparking gaps formed among spaced
electrodes 14, 30 and 32 at one end thereof. An axial connecting
port or bore 38 having a diameter of reduced size extends between
cavity 36 at the other end of the antechamber and a pair of
inverted frusto conical chambers 40 and 42 forming the mouth or
exit nozzle for the spark plug. With this construction, a mixture
of atomized fuel and air can easily enter the antechamber (cavities
34 and 36) and be ignited by a spark discharge across the electrode
gaps defined by electrodes 14, 30, 32. The rapid pressure increase
accompanying such ignition within the confines of the antechamber
will expell a jet or tongue of flame through the port 38 and the
exit nozzle of the plug thereby igniting the main mixture inside
the principal combustion chamber of the engine.
On the other hand, due to the advantageous unique construction of
the present invention, all forms of particle debris or foreign
matter and in particular, engine lubricating oil, are effectively
prevented from entering the antechamber and polluting the spark
plug's electrode gaps as will now be explained with reference to
FIGS. 1 and 3 wherein like reference numberals represent like
parts. It was mentioned previously that the mouth or exit nozzle of
the spark plug is surrounded by a substantially V-shaped groove or
annulus 28. As indicated in the enlarged detail of FIG. 3, this
groove or annulus is machined or otherwise formed so that
preferably one of its sides or walls 44 is coplanar with respect to
the inner wall surface 46 of the engine's principle combustion
chamber when the spark plug is screwed in place. The other side or
wall 48 thus formed by groove 28 extends away from the wall surface
46, at an acute angle, to form a flared or funnel shaped protrusion
extending slightly into the engine's principle combustion chamber
as shown. Concentrically disposed within this flared extremity of
the spark plug is the exit mouth or nozzle previously alluded to
comprising the two inverted frusto conical chambers 40 and 42.
Preferably, the exit mount and more particularly, the two frusto
conical chambers 40 and 42 are formed by machining a second
V-shaped annular groove 50 in the protruding extremity of the outer
shell member after bore 38 has already been formed therein. In
accordance with the present invention the outer frusto conical
chamber 42 and the inverted inner frusto conical chamber 40 formed
by groove 50 are arranged substantially as shown in FIG. 3 with the
diameter of the exit aperture 52 formed by the inter-section of
chamber 42 with the flat outer end face 54 of the flared extremity
of the plug being greater than the diameter of the port or bore 38
as clearly shown in FIGS. 1 and 3. In addition, the diameter
defined by the imaginary base common to the two inverted frusto
conical chambers is greater than the diameter of exit aperture 52
as is also clearly illustrated in FIG. 3. Since the diameter of the
exit mouth will be at a maximum along the imaginary common base
defined by the two inverted frusto conical chambers 40, 42 this
diameter may be referred to hereinafter and in the appended claims
as the exit mouth's "major diameter."
In operation, it will be appreciated that the overhanging
construction of the flat end face 54 of the plug's axially
protruding extremity provides an annular radially extending shield
or baffle that is effective in preventing substantially all
impinging particles of carbon or other debris from entering the
port or bore 38. Only if such particles have a substantially flat
trajectory do they stand a chance of entering the mouth or bore of
the plug. And when this occurs, the entering particles are usually
expelled during the next firing of the plug by the jet of flame
issuing through the port 38.
Moreover, due to the V-shaped grooved annulus 28 surrounding the
protruding extremity of the plug, any oil droplets flowing along
the inner wall 46 of the engine's combustion chamber as indicated
by the arrow 56 in FIG. 3 for example, will be entrapped by the
groove and caused to flow around the flared extremity rather than
flowing over the end face of the plug and into the bore 38 as is
the case in prior art anti-fouling plugs. In the event some
splashed oil does happen to find its way onto the protruding end
face 54 and flows into the mouth defined by chambers 40,42, the oil
will merely collect or pool at the bottom of the exit mouth formed
by groove 50 as represented schematically by reference numeral 58.
When the pooling oil accumulates sufficiently to rise above the
level determined by the lower lip of the exit aperture 52, the
excess will merely flow over this lip under the influence of
gravity and be discharged from the mouth. Because the major
diameter of the exit mouth is axially located relatively nearer to
the exit aperture 52 than it is to the bore 38 as clearly shown in
FIG. 3, and further because the exit aperture 52 is greater in
diameter than the bore 38, the lip formed by the exit aperture will
always be lower in elevation than the bore; hence, the accumulating
pool of oil can not rise sufficiently in the mouth of the plug to
establish backflow into and through the port 38 and thus into the
antechamber of the plug's outer shell. It is thus seen that when
the spark plug of the present invention is disposed in a nominally
horizontal position as called for in great number of modern
internal combustion engines, it is for all intents and purposes
impervious to the deleterious effects of oil and will not foul even
under conditions of severe leaking of engine-valve oil-seals.
Although the improved spark plug of FIGS. 1-3 is preferably of
one-piece integral construction, it will be understood to be within
the contemplation of the present invention to provide an adapter
for conventional spark plugs, which when used together will produce
an improved spark plug configuration having all the advantages and
benefits of the one-piece construction described above in
connection with FIGS. 1-3. Thus, turning now to FIG. 4, there is
shown an alternate preferred embodiment of the present invention
comprising a conventional spark plug generally represented at 58
received within the anti-fouling spark plug adapter generally
designated by reference numeral 60. As shown, adapter 60 forms an
axial extension for the spark plug and toward this end includes an
internally threaded bore or cylindrical passage 62 for
cooperatively engaging the conventional externally threaded inner
end of the spark plug. The adapter 60 also includes a hexagonally
faced flanged portion 64 adapted to be engaged by the usual spark
plug spanner. In all other respects the adapter spark plug
configuration of FIG. 4 is identical to the one-piece plug of FIGS.
1-3 and is used in exactly the same way, that is, the entire
assembly is screwed into a corresponding spark plug receiving port
in the wall of the combustion chamber or cylinder of an internal
combustion engine as depicted by way of illustration in FIG. 4.
Finally, in FIG. 5, there is shown yet another alternative
preferreed embodiment of the present invention comprising an
anti-fouling means 66 integrally formed within the cylinder or
combustion chamber wall 68 of the engine as an axial extension of
the conventional spark plug receiving port 70. The wall 68 has a
slightly greater width than usual to accommodate the anti-fouling
means 66, which latter includes the narrow apertured bore
communicating with the exit mouth or nozzle formed of two inverted
frusto-conical chambers as in both previously described embodiments
of the invention. The anti-fouling means of FIG. 5, however, aside
from its integral construction within the engine or combustion
chamber wall proper differs significantly from both previous
embodiments in that the axial extremity or end face 72 of the unit
is flush or coplanar with respect to the inner wall surface 74 of
the combustion chamber or cylinder. This, in turn, requires that an
annular groove 76 concentrically surrounding the end face 72 be cut
or recessed into the inner wall surface 74 so as to provide means
for entrapping oil flowing along the inner wall surface in
substantially the same way as groove 28 (FIG. 3) accomplishes this
function. And although the flush construction of the end face 72
and the inner wall surface 74 is disclosed herein in connection
with the embodiment of FIG. 5, it will be appreciated that any of
the other preferred forms of the present invention described above
may be modified in a similar manner to suit those applications
where even a slight projection into the combustion chamber or
cylinder of the engine cannot be tolerated.
From the foregoing, it should now be apparent that the present
invention provides a drastically improved spark plug device
including means for effectively preventing fouling of the spark
plug's electrodes despite the presence of oil or other foreign
matter in the engine's combustion chamber and the unfavorable
static horizontal mounting position of the spark plug.
While several preferred embodiments have been disclosed hereinabove
by way of illustration, it will be understood that many
alterations, modifications, and variations may be made within the
spirit and scope of the present invention without departing from
the principles thereof as defined in the appended claims.
* * * * *