Note: Descriptions are shown in the official language in which they were submitted.
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SPARK PLUG PROVIDING IMPROVED
OPERATING CHARACTERISTICS
Technical Field
The present invention generally relates to spark plugs for
igniting the fuel charge in an internal combustion engine, and is
particularly concerned with an improved spark plug construction
which improves combustion pressure, fuel mileage and
diminishes exhaust pollution as compared with known prior art
plugs.
Background of the Invention
Prior art spark plugs are well known. Such spark plugs
typically include a center electrode and a ground electrode
spaced apart from the center electrode. When a sufficient
electrical potential is provided across the gap, a spark jumps
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across the gap. This spark can be used to ignite an air-fuel
mixture within an internai combustion engine.
U. S. Patent No. 5,051,651 details a"cylindrical hole"
that is created around the center electrode by the shielding of
the outer ground electrode. U. S. Patent No. 5,051,651 asserts
that "ignition seeds" multiply inside of this cylindrical hole.
The ground electrode, in all examples, has a "substantially
concave inner surface complimenting the radial face of said
center electrode" (Column 8, line 33). This creates a
concentric curved surface that has an inner radius equal to "the
sum of the radius of the center electrode and a spark gap can
be nearly equal to the radius of the cylindrical hole" (Column
1, line 54).
As seen in Figure 13 of Patent 5,051,651, and in the
language in independent claim #18, the invention relies
specifically on spark strike areas wherein "at Ieast a portion of
each said inner orthogonal sides is provided with a concave
surface having a curvature complimenting the axial face of the
center electrode".
Since all sparks travel along the shortest path, center
electrode to ground electrode, the effective surfaces of U. S.
Patent No. 5,051,651 are similar to other concentric ring
designs (patents #1,748,338; #1,942,242; #1,912,516;
#5,430,346; #5,280,214) where the ground electrode is shaped
in a complimenting radius centered on the same axis as the
center electrode. U. S. Patent No. 5,051.651. at the functional
core where the spark actually jumps, performs similarly to
other concentric ring designs.
However, it is believed by the applicant that concentric
ring designs have shown no performance benefit over standard
spark plug designs.
Reference is also made to U. S. Patent No. 5,612,586, in
which particular importance is placed upon eliminating the 90
degree bend common to a standard spark plug.
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The above prior art patents include some advantageous
features. However, there is always a need for an improved plug
design which provides improved fuel efficiency and reduced
emissions.
Summary of the Invention
The present invention relates to the use of a spark plug
providing edge corners in a tangential relationship with the
central electrode.
Therefore it is an aspect of the present invention to
provide an improved spark plug.
It is a further aspect of the present invention to provide an
improved spark plug ground electrode.
It is a further aspect of the present invention to provide an
improved spark plug which exhibits improved fuel efficiency.
It is a further aspect of the present invention to provide an
improved spark plug which exhibits improved combustion
pressure.
It is a further aspect of the present invention to provide an
improved spark plug which provides decreased pollution.
Other aspects, features, and advantages of the present
invention will become apparent upon reading the following
detailed description of the preferred embodiment of the invention
when taken in conjunction with the drawings and the appended
claims.
Brief Description of the Drawings
Fig. 1 is a top view of a portion of a first embodiment of
the present invention shown in overall view in Fig. 1.
Fig. 2 is a side plan view of the first embodiment shown
in Fig. 1, being a spark plug 10.
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Fig. 3 is a top view of two electrodes, a ground
electrode 51 and a center electrode 20, used in a second
embodiment of the present invention, which could be
considered a "forked" configuration, with two tangential
relationships and one vertex.
Fig. 4 is a top view of two electrodes, a ground
electrode 52 and a center electrode 20, used in a third
embodiment of the present invention, which includes three
segments and three tangential relationships and two vertexes
(a.k.a "vertices").
Fig. 5 is a top view of two electrodes, a ground
electrode 53 and a center electrode 20, used in a fourth
embodiment of the present invention, with six segments, up to
five vertexes, and at-least four tangential relationships.
Fig. 6 is a top view of two electrodes, a ground
electrode 60 and a center electrode 20, used in a fifth
embodiment of the present invention, with four segments,
three vertexes, and four tangential relationships.
Fig. 7 is a top view of two electrodes, a ground
electrode 70 and a center electrode 20, used in a sixth
embodiment of the present invention, which could be
considered a "closed box" configuration, with four tangential
relationships and four vertexes.
Fig. 8 is a top view of two electrodes, a ground
electrode 80 and a center electrode 20, used in a seventh
embodiment of the present invention, which could be
considered a "closed hex box" configuration, with six
tangential relationships and six vertexes.
Fig. 9 is a top view of two electrodes, a ground
electrode 90 and a center electrode 20, used in a eighth
embodiment of the present invention, which could be
considered a "single offset straight electrode" configuration,
with one tangential relationship.
Fig. 10 is a top view of three electrodes, two ground
electrodes 100, 101, and a center electrode 20, used in a ninth
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embodiment of the present invention, which could be
considered a "double offset straight electrode" configuration,
with two tangential relationships.
Fig. 11 is a top view of three electrodes, two ground
5 electrodes 110, 111, and a center electrode 20 used in a tenth
embodiment of the present invention, which could be
considered a "double T electrode" configuration, with two
tangential relationships.
Fig. 12 is a top view of three electrodes, two ground
electrodes 120, 121, and a center electrode 20 used in a
eleventh embodiment of the present invention, which could be
considered an "offset double T electrode" configuration, with
two tangential relationships.
Fig. 13 is a top view of four electrodes, three ground
electrodes 130, 131, and 132 and a center electrode 20 used in
a eleventh embodiment of the present invention, which could
be considered a "triangulated triple T electrode" configuration,
with three tangential relationships.
Fig. 14 is a side elevational view of a typical center
electrode 20, shown underneath a cross-sectional view of a
portion of a ground electrode 140, including a lower corner
edge directed towards the center electrode in a tangential
relationship.
Fig. 15 shows a ground electrode 150 providing a
simple convex curved edge presented to the center electrode
20, with one tangential edge relationship. The transverse
cross-section of the ground electrode is rectangular.
Fig. 16 shows a simple straight edge presented to the
center electrode. One tangential edge relationship is shown.
The cross-section of the ground electrode is rectangular.
Fig. 17 shows the use of four ground electrodes 170,
171, 172 and 173, which combine to present multiple simple
straight edges presented to the center electrode 20. No
tangential edge relationships are shown in this figure, although
four edges could be in the zone referenced in Fig. 26. The
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cross-section of each of the four ground electrodes is
rectangular.
Fig. 18 shows a triangular-shaped ground electrode 180
presenting three edges and three vertexes to the center
electrode 20. Three tangential edge relationships are shown.
The transverse cross-section of each linear segment of the
ground electrode is substantially rectangular.
Fig. 19 is similar to that shown in Fig. 11, and shows a
triangular-shaped ground electrode 190, but with a triangular
center electrode 195. Three tangential edge relationships and
three vertexes are shown in this figure.
Fig. 20 is an open ended design including a ground
electrode 200 presenting three curved edges and two vertexes
to the center electrode 20. Three "curved" tangential edge
relationships are provided under this configuration. Note that a
tangential relationship can be a "straight" tangential
relationship or can include a "curved" tangential relationship.
Fig. 21 is an open ended design including a ground
electrode 210 presenting three straight edges and two vertexes
to the center electrode 20. Three tangential edge relationships
and two vertexes are shown in this figure.
Fig. 22 is an open ended design similar to that shown in
Fig. 21, except with a center electrode 225 shaped substantially
matching the ground electrode 220 geometry, which in this
case is square. Three tangential relationships are shown.
Fig. 23 shows a "forked" design, in which two curved
tangential edge relationships exist, with a single vertex therein.
A ground electrode 220 and a center electrode 230 are shown.
Fig. 24 shows two ground electrodes 240, each having a
"barb" at their end, which serve to substantially surround the
projection of the center electrode 20. Four straight tangential
relationships and two vertexes are shown in this figure.
Fig 25 shows a simple concave curved edge presented to
the center electrode 20 by a ground electrode 250.
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Fig. 26 is a side illustrated view illustrating various
positions 1, 2, and 3 that a ground electrode 260 may be placed
relative to the center electrode, with these three positions 1, 2
and 3 being within a "zone". The positions within the zone
provide such that any of the positions expose the lower edge of
the ground electrode to the center electrode's outer edge,
which, in the inventor's opinion at the time of filing, can
create a"chimney" effect for the intake gases.
Fig. 27 is a side cross-sectional view of the embodiment
shown in Fig. 1(taken through the center longitudinal axis of
the center electrode 20) with the lower edges of the ground
electrode 270 presented above the center electrode in a
substantially tangential relationship to the peripheral projection
to the center electrode.
Fig. 28 is a view similar to Fig. 27, but the cross-section
of the ground electrode 280 has been streamlined to offer less
resistance to the flame front's propagation.
Fig. 29 is a view similar to that of Fig. 28, but the
ground electrode 290 has been reduced to a single edge, and
supported by an arc, as seen in electrode design shown in Fig.
25. Such a design could also apply to the view of Fig. 15. The
cross-section could be of any shape other than that shown, that
presents an edge (straight or otherwise) as the closest surface
to the top edges of the center electrode 20.
Fig. 30 shows an embodiment including multiple ground
electrodes 300, 301, and 302 (a fourth electrode ground, not
shown, may also be used) which provides multiple straight
edges presented to the center electrode's top via straight angled
upwardly and inwardly. The angle is not believed to be as
important as the final position of the edges of the tips of the
elongate members.
Fig. 31 is a side cross-sectional view of a configuration
generally similar to that shown in, for example, Fig. 1, except
the cross-section of the ground electrode 310 has a "diamond"
shape, presenting edges to the top circular edge of the center
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electrode 20. This design could promote better flow for the
flame resulting from the spark ignition due to the chamfers
above and below the ground electrode edges.
Fig. 32 is a modification of that shown in Fig. 1, except
a simple chamfer is provided on the top surface of the ground
electrode 320. This could gain some of the benefits of the
design shown in Fig. 31, but would appear to be easier to
manufacture.
Fig. 33 is a view of an embodiment including a ground
electrode which is similar to Fig. 1, except that a simple notch
has been cut into the center electrode 335 to improve spark
efficiency.
Fig. 34 is a side cross-sectional view of an embodiment
similar to that of Fig. 1, including a ground electrode 340,
except that a "necked-down" section is provided at the top of
the center electrode 345, creating a "fine wire" discharge tip to
the center electrode.
Fig. 35 shows a ground electrode 350 edge presented
from above, through single (as shown) or multiple (not shown)
stems that support the "important" edge Also, the center
electrode 355 has a chamfer at the tip.
Fig. 36 shows a configuration which includes
"maximized edge-to-edge presentation" of two edges defined
by the center and ground electrodes 365, 360, respectively.
While possibly more expensive to manufacture than other
embodiments, this design presents a less sheilded edge-to-edge
spark to the combustion chamber. The small sizes of the
electrodes are also believed to serve to reduce blockage to the
incoming fule charge and the existing flame kernel.
Fig. 37 is a view of a spark plua having a ground
electrode 370 similar to that of Figs. 1 and 2, except that a
chisel point center electrode 375 is used.
Fig. 38 is a view of a spark plug having a single point
center electrode 385, with a ground electrode 380 being
similar to that shown in Figs. 1 and 2.
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Fig. 39 is a view of a series of center electrode
configurations which may be used with other ground
electrodes within this description, including a chisel point 395-
A, pyramid point 395-B, a V-groove 395-C, a dimpled center
395-D, a polygon 395-E, a single point 395-F, multiple edges
395-G, a chamfer point 395-H, a hollow cylinder 395-I, a
hollow polygon 395-J,and a necked down configuration 395-K.
Fig 40A and B are top and side plan views, respectively,
of a configuration including a T-shaped center electrode 405
having T-shaped ends each defining an edge, and a pair of
ground electrodes 400, 401 likewise each defining an edge.
The edges of the center electrode are presented to the edges of
the ground electrodes in a one-to-one relationship.
Figs 41 A and 41 B are top and side plan views,
respectively, of a configuration including and L-shaped center
electrode 415 and a ground electrode 410, with curved
tangential edges. Note that two segments could be used such as
in Figs. 40A and 40B, or more than two segments could be
used, either with this configuration of the Figs. 40A/40B
configuration.
Figs. 42A/42B show a configuration which includes a
center electrode 425 and a ground electrode 420, combining to
form three tangential relationships.
Fig. 43 is a configuration which includes a center
electrode 20 and a ground electrode 430, which provides
vertical and horizontal spacing between the two referenced as
G 1 and G2, respectively. Preferably G 1 is greater than or
equal to zero and G2 is greater than or equal to zero. This is
another way to illustrate the "zone" concept of Fig. 26.
Fig. 44 is an illustrative top plan view of an exemplary
center electrode 20 and two exemplary ground electrodes 440,
441, further illustrating the tangential relationship which is
one feature of the present invention. As may be seen, a
"tangential" relationship includes not only the "case 1"
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relationship of the elements 20, 440, but also the "case 2"
relationship of the elements 20, 441.
Fig. 45 is an illustrative top plan view of an exemplary
center electrode 20 and a two-pronged ground electrode 450,
5 which is similar to that shown in Fig. 3 but has shorter prongs
which provide two tangential relationships 453, 454, as shown
in the case 2 example in Fig. 44. An intermediate vertex 455
is also shown.
Fig. 46 is a "wide-box" configuration which is similar to
10 that of Fig. 1, except that instead of having four tangential
relationships, the four edges of the ground electrode 460 are
outside the projection of the center electrode, and in the "zone"
of Fig. 26. In the inventor's opinion at the time of filing, this
provides additional room under the "intake charge flow"
concept illustrated in Fig. 26.
Fig. 47 is a "wide-fork" configuration which is similar
to that of Fig. 3, except that instead of having two tangential
relationships, the two edges of the ground electrode 470 are
outside the projection of the exemplary center electrode 20,
and in the "zone" of Fig. 26. In the inventor's opinion at the
time of filing, this provides additional room under the "intake
charge flow" concept illustrated in Fig. 26.
Fig. 48 illustrates a believed difference in concentric and
nonconcentric electrode properties, showing a concentric
ground electrode 480, an "open" ground electrode 481, each in
association with a typical center electrode 20. As may be seen,
open electrode surfaces are believed by the inventor to tend to
encourage flame kernel propagation.
Detailed Description of the Preferred Embodiment
Generally described, the present invention is directed
towards the use of a spark plug having a conventional center
electrode and one or more ground electrodes, each of which
defines at least one lower corner edae which is substantially
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tangentially oriented relative to the periphery of the
substantially round electrode below.
One configuration contemplated under the present
invention can be referred to as a "box" plug, shown in Figs. 1
and 2. The "box" plug uses an electrode that is substantially
in the shape of a square that appears to "encircle" the spark
plug's center electrode, when viewed from above. However,
in fact, as shown in Fig. 2, the box does not encircle the spark
plug's center electrode, as there is a gap (0.025" in the case of
one test) defined between the upper round end surface of the
center electrode and the plane in which the downwardly-
directed lower surfaces of the split prong members lie.
As may be seen, the electrode 30 includes two end
prongs 32 which initially diverge but then eventually
converge. The two end prongs 32 each include two segments
34 of substantially equal length. Two of these segments could
be considered as the "diverging" segments 34, and the other
two could be considered as the "converging" segments 34.
This would mean that each prong includes one "diverging"
segment and one "converging" segment.
An "Elbow" could be considered as connecting the
diverging segment of a particular segment to its corresponding
converging segment. Such elbows (two in the Fig. 1 version)
are shown as being substantially in a vertical plane extending
through the central longitudinal axis of the center prong.
The ground electrode could be considered to have three
vertexes, a main vertex 40 and two elbow inner vertexes 41
It may be understood that the transverse cross sections
of the segments 34 are substantially rectangular, being in one
configuration 0.050" wide and 0.050" thick. Such a cross
section provides four outwardly-directed, substantially linear
(at least not near the bends) corner edges, (also shown in Fig.
14). It is believe that the relationship of at least the inner
lower corner edges relative to the center electrode provides
improved performance. Such a relationship will be referred
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to as a tangential relationship, with four tangential
relationships provided in the Fig. 1 configuration, one for each
segment 34.
It should be understood that the center electrode as
shown in Fig. 2 shall be referenced in this application as an
"upwardly"-extending center electrode. However, this is for
reference purposes only and should not be understood as
limiting. In operation such an electrode can be oriented in
many difference directions while in use.
Other Embodiments
Other ground electrode embodiments are contemplated
under the present invention.
Fig. 3 is a top view of two electrodes, a ground
electrode 51 and a center electrode 20, used in a second
embodiment of the present invention, which could be
considered a "forked" configuration, with two tangential
relationships and one vertex.
Fig. 4 is a top view of two electrodes, a ground
electrode 52 and a center electrode 20, used in a third
embodiment of the present invention, which includes three
segments and three tangential relationships and two vertexes
(a.k.a "vertices").
Fig. 5 is a top view of two electrodes, a ground
electrode 53 and a center electrode 20, used in a fourth
embodiment of the present invention, with six segments, up to
five vertexes, and at least four tangential relationships.
Fig. 6 is a top view of two electrodes, a ground
electrode 60 and a center electrode 20, used in a fifth
embodiment of the present invention, with four segments,
three vertexes, and four tangential relationships.
Fig. 7 is a top view of two electrodes, a ground
electrode 70 and a center electrode 20, used in a sixth
embodiment of the present invention, which could be
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considered a "closed box" configuration, with four tangential
relationships and four vertexes.
Fig. 8 is a top view of two electrodes, a ground
electrode 80 and a center electrode 20, used in a seventh
embodiment of the present invention, which could be
considered a "closed hex box" configuration, with six
tangential relationships and six vertexes.
Fig. 9 is a top view of two electrodes, a ground
electrode 90 and a center electrode 20, used in a eighth
embodiment of the present invention, which could be
considered a "single offset straight electrode" configuration,
with one tangential relationship.
Fig. 10 is a top view of three electrodes, two ground
electrodes 100, 101, and a center electrode 20, used in a ninth
embodiment of the present invention, which could be
considered a "double offset straight electrode" configuration,
with two tangential relationships.
Fig. 11 is a top view of three electrodes, two ground
electrodes 110, 111, and a center electrode 20 used in a tenth
embodiment of the present invention, which could be
considered a "double T electrode" configuration, with two
tangential relationships.
Fig. 12 is a top view of three electrodes, two ground
electrodes 120, 121, and a center electrode 20 used in a
eleventh embodiment of the present invention, which could be
considered an "offset double T electrode" configuration, with
two tangential relationships.
Fig. 13 is a top view of four electrodes, three ground
electrodes 130, 131, and 132 and a center electrode 20 used in
a eleventh embodiment of the present invention, which could
be considered a "triangulated triple T electrode" configuration,
with three tangential relationships.
Fig. 14 is a side elevational view of a typical center
electrode 20, shown underneath a cross-sectional view of a
portion of a ground electrode 140, including a lower corner
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edge directed towards the center electrode in a tangential
relationship.
Fig. 15 shows a ground electrode 150 providing a
simple convex curved edge presented to the center electrode
20, with one tangential edge relationship. The transverse
cross-section of the ground electrode is rectangular.
Fig. 16 shows a simple straight edge presented to the
center electrode. One tangential edge relationship is shown.
The cross-section of the ground electrode is rectangular.
Fig. 17 shows the use of four ground electrodes 170,
171, 172 and 173, which combine to present multiple simple
straight edges presented to the center electrode 20. No
tangential edge relationships are shown in this figure. The
cross-section of each of the four ground electrodes is
rectangular.
Fig. 18 shows a triangular-shaped ground electrode 180
presenting three edges and three vertexes to the center
electrode 20. Three tangential edge relationships are shown.
The transverse cross-section of each linear segment of the
ground electrode is substantially rectangular.
Fig. 19 is similar to that shown in Fig. 11, and shows a
triangular-shaped ground electrode 190, but with a triangular
center electrode 195. Three tangential edge relationships and
three vertexes are shown in this figure.
Fig. 20 is an open ended design including a ground
electrode 200 presenting three curved edges and two vertexes
to the center electrode 20. Three "curved" tangential edge
relationships are provided under this configuration. Note that a
tangential relationship can be a "straight" tangential
relationship or can include a "curved" tangential relationship.
Fig. 21 is an open ended design including a ground
electrode 210 presenting three straight edges and two vertexes
to the center electrode 20. Three tangential edge relationships
and two vertexes are shown in this figure.
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Fig. 22 is an open ended design similar to that shown in
Fig. 21, except with a center electrode 225 shaped substantially
matching the ground electrode 220 geometry, which in this
case is square. Three tangential relationships are shown.
5 Fig. 23 shows a "forked" design, in which two curved
tangential edge relationships exist, with a single vertex therein.
A ground electrode 220 and a center electrode 230 are shown.
Fig. 24 shows two ground electrodes 240, each having a
"barb" at their end, which serve to substantially surround the
10 projection of the center electrode 20. Four straight tangential
relationships and three vertexes are shown in this figure.
Fig 25 shows a simple curved edge presented to the
center electrode 20 by a ground electrode 250.
Fig. 26 is a side illustrated view illustrating various
15 positions 1, 2, and 3 that a ground electrode 260 may be placed
relative to the center electrode, with these three positions 1, 2
and 3 being within a "zone". The positions within the zone
provide such that any of the positions expose the lower edge of
the ground electrode to the center electrode's outer edge,
which, in the inventor's opinion at the time of filing, can
create a "chimney" effect for the intake gases.
Fig. 27 is a side cross-sectional view of the embodiment
shown in Fig. 1(taken through the center longitudinal axis of
the center electrode 20) with the lower edges of the ground
electrode 270 presented above the center electrode in a
substantially tangential relationship to the peripheral projection
to the center electrode.
Fig. 28 is a view similar to Fig. 27, but the cross-section
of the ground electrode 280 has been streamlined to offer less
resistance to the flame front's propagation.
Fig. 29 is a view similar to that of Fig. 28, but the
ground electrode 290 has been reduced to a single edge, and
supported by an arc, as seen in electrode design shown in Fig.
25. Such a design could also apply to the view of Fig. 15. The
cross-section could be of any shape other than that shown, that
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presents an edge (straight or otherwise) as the closest surface
to the top edges of the center electrode 20.
Fig. 30 shows an embodiment including multiple ground
electrodes 300, 301, and 302 (a fourth electrode ground, not
shown, may also be used) which provides multiple straight
edges presented to the center electrode's top via straight angled
upwardly and inwardly. The angle is not believed to be as
important as the final position of the edges of the tips of the
elongate members.
Fig. 31 is a side cross-sectional view of a configuration
generally similar to that shown in, for example, Fig. 1. except
the cross-section of the ground electrode 310 has a "diamond"
shape, presenting edges to the top circular edge of the center
electrode 20. This design could promote better flow for the
flame resulting from the spark ignition due to the chamfers
above and below the ground electrode edges.
Fig. 32 is a modification of that shown in Fig. 1, except
a simple chamfer is provided on the top surface of the ground
electrode 320. This could gain some of the benefits of the
design shown in Fig. 31, but would appear to be easier to
manufacture.
Fig. 33 is a view of an embodiment including a ground
electrode which is similar to Fig. 1, except that a simple notch
has been cut into the center electrode 335 to improve spark
efficiency.
Fig. 34 is a side cross-sectional view of an embodiment
similar to that of Fig. 1, including a ground electrode 340,
except that a "necked-down" section is provided at the top of
the center electrode 345, creating a "fine wire" dQtip to
the center electrode. discharge
Fig. 35 shows a ground electrode 350 edge presented
from above, through single (as shown) or multiple (not shown)
stems that support the "important" edge Also, the center
electrode 355 has a chamfer at the tip.
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Fig. 36 shows a configuration which includes
"maximized edge-to-edge presentation" of two edges defined
by the center and ground electrodes 365, 360, respectively.
While possibly more expensive to manufacture than other
embodiments, this design presents a less shielded edge-to-edge
spark to the combustion chamber. The small sizes of the
electrodes are also believed to serve to reduce blockage to the
incoming fuel charge and the existing flame kernel.
Fig. 37 is a view of a spark plug having a ground
electrode 370 similar to that of Figs. 1 and 2, except that a
chisel point center electrode 375 is used.
Fig. 38 is a view of a spark plug having a single point
center electrode 385, with a ground electrode 380 being
similar to that shown in Figs. 1 and 2.
Fig. 39 is a view of a series of center electrode
configurations which may be used with other ground
electrodes within this description, including a chisel point 395-
A, pyramid point 395-B, a V-groove 395-C, a dimpled center
395-D, a polygon 395-E, a single point 395-F, multiple edges
395-G, a chamfer point 395-H, a hollow cylinder 395-I, a
hollow polygon 395-J,and a necked down configuration 395-K.
Fig 40A and B are top and side plan views, respectively,
of a configuration including a T-shaped center electrode 405
having T-shaped ends each defining an edge, and a pair of
ground electrodes 400, 401 likewise each defining an edge.
The edges of the center electrode are presented to the edges of
the ground electrodes in a one-to-one relationship.
Figs 41 A and 41 B are top and side plan views,
respectively, of a configuration including and L-shaped center
electrode 415 and a ground electrode 410, with curved
tangential edges. Note that two segments could be used such as
in Figs. 40A and 40B, or more than two segments could be
used, either with this configuration of the Figs. 40A/40B
configuration.
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Figs. 42A/42B show a configuration which includes a
center electrode 425 and a ground electrode 420, combining to
form three tangential relationships.
Fig. 43 is a configuration which includes a center
electrode 20 and a ground electrode 430, which provides
vertical and horizontal spacing between the two referenced as
G 1 and G2, respectively. Preferably G 1 is greater than or
equal to zero and G2 is greater than or equal to zero. This is
another way to illustrate the "zone" concept of Fig. 26.
Fig. 44 is an illustrative top plan view of an exemplary
center electrode 20 and two exemplary ground electrodes 440,
441, further illustrating the tangential relationship which is
one feature of the present invention. As may be seen, a
"tangential" relationship includes not only the "case 1"
relationship of the elements 20, 440, but also the "case 2"
relationship of the elements 20, 441.
Fig. 45 is an illustrative top plan view of an exemplary
center electrode 20 and a two-pronged ground electrode 450,
which is similar to that shown in Fig. 3 but has shorter prongs
which provide two tangential relationships 453, 454, as shown
in the case 2 example in Fig. 44. An intermediate vertex 455
is also shown.
Fig. 46 is a "wide-box" configuration which is similar to
that of Fig. 1, except that instead of having four tangential
relationships, the four edges of the ground electrode 460 are
outside the projection of the center electrode, and in the "zone"
of Fig. 26.
Fig. 47 is a "wide-fork" configuration which is similar
to that of Fig. 3, except that instead of having two tangential
relationships, the two edges of the ground electrode 470 are
outside the projection of the exemplary center electrode 20,
and in the "zone" of Fig. 26. In the inventor's opinion at the
time of filing, this provides additional room under the "intake
charge flow" concept illustrated in Fig. 26.
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The Tangential Relationship
As noted above, in some instances it is desired to have a
one or more straight edges in a tangential relationship with the
circular (a.k.a "round") upper edge of the ground electrode.
This will be referred to as a "straight edge tangential
relationship" in that the straight edge defined by the ground
electrode presents one or more straight edges such that each
edge is in a tangential relationship to the center electrode's
circumferential projection. Such is shown in, for example
only, Figs. 1, 3, 4, 9, and 10, although many others are
shown).
However, it should also be understood that a "curved
edge tangential relationship is also contemplated under one of
the inventions disclosed herein, which is shown in, for example
only, Figs. 15, 23, and 25.
The important point to note is that the spark will connect
between the center electrode and the closest ground. The actual
placement of the ground electrode's prongs may be anywhere
adjacent to or outside the peripheral (which need not
necessarily be round) projection of the center electrode, at a
chosen height at or above the center electrode's tip.
It should be understood that certain aspects of the
invention contemplate the use of some offset of the tangential
relationship, such as shown in Figs 17 and 26.
The Straightness of the Edges
As noted above, in some instances it is desired to have a
straight edge in a tangential relationship with the curved upper
edge of the ground electrode. However, it should be
understood that certain aspects of the invention contemplate the
use of curved edges in such a tangential relationship.
The Zone Concept
Reference is made to Figs. 26 to illustrate the "Zone"
concept, in which any of the positions shown expose the lower
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edge of the ground electrode to the center electrode's outer
edge (a.k.a. its "upper peripheral edge", which could be
circular).
This is another related concept of the related invention,
5 in which the edges which are presented or exposed to each
other are not necessarily tangential, but they do present
themselves to each other such that the edges are the closest
parts of the two electrodes to each other, or are at least as
close as any other two parts of the electrodes, within the
10 region of spark. It is believed at the time of filing that the
"unshielding" of the top of the center electrode by placing the
ground electrode outside the periphery is an advantageous
concept above and separate from the tangential and-or vertex
concepts. Again it is believed that placing the lowest portion
15 of the ground electrode's "active edge" at or above the center
electrode allows the intake charge gases to flow more easily
into the spark zone.
The Vertexes
20 It is believed at the time of filing that the combination of
the tangential relationship and the vertexes, which is provided
in some of the applicant's embodiments (for example those
shown in Figs. 1, 3, 4, 5, 6, and others) provides a distinct
improvement over the prior art. Some of such vertexes
provide a vertical "opening" or a "chimney effect" which is
believed to provide improved flame characteristics.
Furthermore, it is believed at the time of filing that the
combination of the "zone" relationship and the vertexes, which
is provided in some of the applicant's embodiments, provides a
distinct improvement over the prior art
Processes Used
The simple shapes of the ground electrodes described in
this application can be created by a secondary and subsequent
operations on the standard wire-fed electrode currently in use
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in the industry. A mandrel of specific design can be used to
form the various segments of each electrode. Alternately, a
stamped electrode can be made using a die to create the
specific configuration. The stamped electrode could then be
welded to the spark plug base per usual practice. Instead of
stamping, the electrode shape could be created by laser cutting,
water jet cutting, chemical etching, forging, casting, powdered
metal forming, etc. Any electrodes using these methods would
then be welded to the spark plug base at the appropriate
position.
With respect to the configurations shown in Figures 9
and 10, these electrode configurations can be created with little
change to the current wire-feed arrangement. The offset with
respect to the center electrode can be created in the basic wire
feed machine set up, or by the use of a secondary operation
that creates the specific alignment of the conventional sidewire.
Miscellaneous Comments
In, for example, Fig. 1, the thickness of the ground
electrodes, including the end portions (including their
segments), is as known in the art, or approximately 0.050",
although the thickness can be 0.040 - 0.065", although it could
be 0.010"- 0.150", or other dimensions without departing
from the spirit and scope of the present invention. The width
of the "stem" can be 0.075 - 0.125" , although it could be
0.010"- 0.150", or other dimensions without departing from
the spirit and scope of the present invention.
It is believed that the width of the prongs is not critical,
but the sharpness of the edge(s) is important. However, in one
preferred embodiment, the prongs are 0.050" wide and 0.050"
thick, although each of these dimensions could be 0.010"-
0.150", or other dimensions without departing from the spirit
and scope of the present invention.
It should also be understood that it is not believed that
the ground electrode be square or rectangular, as long as it
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includes a sharp corner which presents the lower corner edge
to the center electrode as shown in Fig. 14 or 26.
The center electrode diameter can be 0.010"- 0.150".
The thickness of the electrode "stem", where applicable, can be
0.040 - 0.065" , although it could be 0.010"- 0.150", or other
dimensions without departing from the spirit and scope of the
present invention.
The materials used throughout are such as known in the
art, including presently-used "premium" materials (e.g.,
platinum).
Comparison to the Prior Art
In contrast to U. S. Patent No. 5,051,651, in the present
invention, the striking surface for the spark on the ground
electrode has been shaped in an open concave curve, a straight
line, or even a convex curve in order to clear the way for the
flame kernel to expand away from the sparking point. This
occurs at a microscopic level such that any hint of a concentric
radius on the striking surface has a negative effect on flame
kernel growth. This discovery of the extreme sensitivity of
the combustion process to this striking surface radius is one
important part of one of our inventions.
It is believed that concentric ring designs, no mater how
minimal the length of the concentrically curved section is,
perform no better in practice than conventional spark plug
designs. This is the substantial difference between the Pyrotek
invention and the one described in patent #5,051,651. The
latter always relies on a "hollow cylindrical ground
electrode ... by which combustion gas can gush out from..."
(Column 2, line 59).
The ground electrode spacing in Patent #5,051,651 is
always spaced away from the center electrode by a gap. In the
Pyrotek invention, tangential relationships are useful due to the
open nature of the striking surface. Any concentric radius
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imparted to the striking surface in a tangential relationship
would severely constrain the flame kernel generation.
Finally, Patent #5,051,651 incorporates two mounting
stems which have a certain amount of shielding effect on the
flame kernel, particularly when compared to the single stern
of the preferred embodiment of the Pyrotek invention.
Conclusion
While this invention has been described in specific detail
with reference to the disclosed embodiments, it will be
understood that many variations and modifications may be
effected within the spirit and scope of the invention as
described in the appended claims.
