Patent Application
20140292177
The invention generally pertains to spark plugs for internal combustion engines and more specifically, to a spark plug that creates a spark flanked on the same plane with an offset positive electrode firing tip and a negative ground electrode beveled tip.
Previously, many types of multi-gap spark plugs have been used to provide an effective means for to igniting a gaseous mixture of fuel and air within an engine combustion chamber. A spark plug typically utilizes high voltage electric current to create a spark that facilitates combustion, thus generating power to drive an internal combustion engine.
A search of the prior art did not disclose any patents that possess the novelty of the instant invention; however the following U.S. patents are considered related:
Dukelow in U.S. Pat. No. 2,136,206 discloses a spark plug for an internal combustion engine. The spark plug has an intermediate electrode which is insulated from both the shell and the central electrode providing two gaps resulting in an operation that is more efficient and that provide a hotter spark.
Kagawa et al. in U.S. Pat. No. 5,189,333 discloses a multi-gap spark plug having a metallic shell into which a tubular ceramic insulator is enclosed. A center electrode is enclosed in the insulator and a plurality of L-shaped outer electrodes, having a vertical piece and a lateral piece which depend from the front end of the shell surrounding the insulator. The lateral piece has an inner surface parallel with a front end of the insulator. The distance between the insulator and the outer electrode is from 0.3 mm to 1.2 mm.
U.S. Pat. No. 6,095,124 issued to Matsubara et al. discloses a spark plug having a center electrode, a ground electrode and an insulator. A discharge high voltage is applied across the center electrode and the ground electrode such that a polarity of the center electrode is positive and that of the ground electrode is negative. The high voltage causes a spark discharge to be generated between the firing surface of the ground electrode and a tip end portion of the center electrode.
Sakura in U.S. Pat. No. 6,750,597 discloses a method of manufacturing a spark plug having a center electrode, an insulator disposed around its center, and a ground electrode in opposition to the center electrodes to form, a spark discharge gap therebetween. A high melting point metal is welded to at least the free end portion of the ground electrode.
U.S. Pat. No. 7,922,551 of Tozzi discloses a method and apparatus to maximize spark plug life and reduce electrode erosion by spreading discharge energy over a wide surface area while maintaining safe electrode temperature. Energy is spread with a swirling effect created by a periphery hole in an end cap. The flow field generated at the electrodes prevent electrical shorts due to water condensation and provides an effective heat transfer path.
Kanao et al. in U.S. Pat. No. 8,258,686 discloses a spark plug which includes a tubular metal shell, an insulator, a cylindrical center electrode and a ground electrode. The ground electrode has an inclined portion, and a strait portion with a bend therebetween. The inclined portion extends obliquely with respect to the axial direction of the center electrode providing a base end of the ground electrode. The straight portion of the center electrode extends substantially parallel to the axial direction of the center electrode from the bend to a tip end of the ground electrode.
Wang in U.S. Pat. No. 8,269,405 discloses a neutral electrode spark plug consisting of a cylindrical metallic shell having a tubular ceramic insulator, an insulator tip enclosed therein, and a central electrode surrounded by the ceramic insulator. The central electrode has a firing tip extending from the insulator tip. A neutral electrode extends from the insulator tip providing a first spark gap that is separated from the central electrode. A side ground electrode is attached to the metallic shell and is laterally aligned with the central electrode and the neutral electrode. The ground electrode provides a second spark gap that is separated from the neutral insulator and a third spark gap formed with the ground electrode.
Hill in U.S. Pat. No. 8,388,396 discloses a spark plug using a space between an electrode body and an electrode cage. The electrode cage extends over the electrode body such that the actuate members of the cage are equidistantly spaced from the spherical electrode body.
The spark plug was known as early as 1860 and patented in the United States by Nikola Tesla in 1898. Since then there have been substantial improvements to spark plug design in an attempt to provide either better ignition, longer life, or both. Such improvements include the use of two or three ground electrodes surrounding a central electrode. Recessed central electrodes have also been developed utilizing single notches in the tip of the ground or central electrodes have been used in an attempt to provide a longer useful life when the spark gap widens during electrical discharge wear permitting the spark to move closer to another spot when a current of electrons surge across the gap. In most cases a conventional spark plug utilizes a vertical spark gap between the center electrode and the ground electrode or neutral.
The primary object of the invention is to provide an improved spark plug by providing a lateral or cross fire spark path utilizing sharp edges in the electrodes which have been known to decrease demand voltage across the spark gap and to also provide a more constant and stable ignition. A ground or neutral electrode is angled into the offset or center electrode on the same plane, providing sharp edges for the spark gap.
The positioning of the cross fire allows the spark kernel to develop considerably deeper into the cylinder bore, thereby resulting in a cleaner and more powerful ignition of the fuel and air mixture.
An important object of the invention is the inclusion of a beveled ground electrode which produces a distinct sharp edge between the beveled end and the firing tip of the center electrode.
Another important object of the invention is that the length and position of the electrodes is easily accomplished in the basic design as it requires only a small modification to the components and positioning tooling. The manufacturing process is therefore not fundamentally affected, thus allowing the improvement to be realized by the end user with little or no extra expense.
These and other objects and advantages of the present invention will become apparent from the subsequent detailed description of the preferred embodiment and the appended claims taken in conjunction with the accompanying drawings.
The best mode for carrying out the invention is presented in terms that disclose a preferred and a second embodiment of a lateral traverse discharge spark plug for an internal combustion engine. The preferred embodiment of the lateral traverse discharge spark plug 10, as shown in
The ceramic insulator 22 is essentially tubular in shape with a cylindrical shaped bottom portion converging into an attachment end 28 that extends from the metallic shell 20 from 0.10 inches (0.254 mm) to 0.20 inches (0.508 mm), as illustrated in
The offset center electrode 30 is surrounded by the ceramic insulator 22 within the metallic shell 20. The offset center electrode 30 terminates with a firing tip 36 that extends from the attachment end 28 of the ceramic insulator 22. The center electrode 30 is offset, as illustrated in
The offset center electrode 30 has a diameter on a firing tip end 36 preferably ranges from 0.09 inches (0.229 mm) to 0.10 inches (0.254 mm) extending from the insulator 28. The diameter of the central electrode 30 permits the electrons to be emitted where the electrical field strength is greatest, particularly where the area is the smallest and a sharp edge is provided. The offset center electrode integral circular-shaped peripheral firing tip 36 is illustrated in
The ground electrode 38, as shown best in
The offset center electrode 30 and the ground electrode 38 protrude from the cylindrical metallic shell 20 attachment end 28 of the end of the ceramic insulator 22 in a terminally aligned orientation with the offset center electrode 30. The ground electrode 38 is spaced from the firing tip 36 and the beveled tip 40 no less than double the diameter of the firing tip 36.
The spark plug metallic shell 20 and ground electrode 38 are preferably plated with chromium, however other plating materials may also be used for corrosion protection.
The second embodiment, as illustrated in
While the invention has been described in detail and pictorially shown in the accompanying drawings, it is not to be limited to such details, since many changes and modifications may be made to the invention without departing from the spirit and scope thereof. Hence, it is described to cover any and all modifications and forms which may come within the language and scope of the appended claims.
