US1359437A - Spark-plug - Google Patents

Description

E. H. SCHWAB.

SPARK PLUG.

APPLICATION FILED MAR. 3. 1919.

UNITED l STATES PATENT OFFICE.

EDWARD H. SCHWAB, 0F SOUTH BETHLEHEM, PENNSYLVANIA.

SPARK-PLUG. l

To alla@ hom it 'may concern:

Be it known that I, EDWARD H. SCHWAB, a citizen of the United States, residing at South Bethlehem, in the county of Northampton and State of Pennsylvania, have made certain new and useful Improvements in Spark-Plugs; and I do hereby declare the followingto be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings; and to the figures of reference marked thereon, which form a part of this speciiication.

This invention relates to spark-plugs for internal combustion engines, and has for its object to provide a composite insulation for spark-plugs in which porcelain and mica are employed.

A further object ofthe invention is to provide a spark-plug having an insulation of porcelain and mica, in which a novel construction is employed for mounting the porcelain and mica members of the insulation on the electrode spindle.

With these and other objects in vieW the invention consists of the novel construction of the electrode spindle; in the novel construction of mounting the porcelain and mica members of the insulation, and in certain details of construction and combinations of parts, all of which will be first fully described and afterward specifically pointed out in the appended claims.

Referring to the accompanying drawing:

The figure is a vertical sectional view of a spark-plug-constructed in accordance with this invention.

Referring to the drawing by reference numerals:

1 indicates the spark-plug having a metal shell 2, threaded at 3 for connection with a motor, and formed preferably hexagonal at 4 to receive a suitable Wrench. The shell 2 is internally chambered to receive the insulation and is provided with an internal seat or shoulder 5 and has a female threaded portion 6 to receive the male threaded portion 7 of the gland or bushing 9, said gland or bushing 8 being shouldered at 10 for engagement with the porcelain member of the insulation, as will be presently described. i

Referring now to the insulation 11, it will be seen that the same includes an inner Specification of Letters Iatent.

Application led lMarch 3,

Patented Nov. 16, 1920.

1919. serial No. 280,339.

porcelain member 12, and an outer mica member 13. "lhe porcelain member 12 is provided exterlorly with a shoulder 14 complemental to the shoulder 5 in the shell, and

is internally bored to receive the electrodespindle 15. As shown this bore is preferably of three diameters the lowermost and smallest diameter' 16 receiving the electroderod 17, while the central and intermediate diameter 18 isprovided with a female thread 19 to receive the male threaded portion 20 of the electrode spindle 15, a shoulder 21 being formed at the juncture of the said central or intermediate diameter 18 of the bore and the uppermost and largest diameter 22.

The electrode spindle 15 receives the electrode rod 17, and directly above the threaded portion thereof, is a flange or shoulder 23 complemental to the shoulder 21 in the porcelain insulating member. `A similar flange or shoulder 24 is formed on the spindle 15 near the head thereof, between which shoulders 23 and 24, a wrapping of mica 25 is positioned, as shown in the drawing. The outer end of the spindle 15 is threaded at 26 to receive a suitable terminal head 27, while a flange 28 is formed on the spindle directly under the said threaded portion 26 thereof.

The insulation is assembled as follows:

A suitable gasket 29 is passed on the spindle 15 and against the flange 28 thereof; the mica wrapping 25 is applied between the flanges 23 and 24, and the mica washers which form the mica section 13 are then passed on the spindle and over and around the mica wrapping 25. The spindle 15 is then threaded into the porcelain member 12, a suitable cement being employed at the threaded 1,5 is 'progressed'A into the porcelain member 12 until the flange or shoulder 23 thereof is seated firmly on the complemental shoulder 21 in the porcelain. This threading of the spindle 15 into the porcelain member 12 carries the mica section 13 down upon the flat face 30 of the porcelain member 12, and tightly compresses the mica washers 4thereofY between said porcelain member 12 portion thereof, and said spindle- In assembling the insulation in the shell, a suitable soft gasket 31 is disposed on the seat or shoulder 5 to provide a as-tight joint between the insulation and t e shell. After the insulation is inserted, a suitable gasket 32 is placed on the top of the porceain member l2, and the gland or bushing 9 is threaded into the shell with pressure sufficient to effectively seat the porcelain member l2 on its gasket 31.

A ground electrode of any approved type is provided, as for instance, a transverse rod 33, having both ends embedded in the shell, and spaced from the central electrode rod ll to provide a suitable spark-gap.

The advantages iowing from the foregoing construction will be at orce apparent to those skilled in the art, as in a simple and inexpensive manner, a particularly durable and eiiicient plug is provided; one in which the tendency of the porcelain to fracture is reduced to the minimum, and in which the mica components are remote from the injurious action of oil and the direct, intense heat of the flame in the motor. A

Having thus fully describedthe invention, I wish it to be understood that while the construction shown in the drawing and described in this specification discloses the preferred embodiment of this invention nevertheless the same is susceptible oi changes and modifications in the construction and arrangement of the parts, and that I consider myself clearly entitled to all such changes and modifications as fall within the limit and scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. A spark-plug includin a metal shell and gland, an insulation inc uding an inner porcelain member and an outer mica member, the porcelain member bein internally threaded, an electrode spin e passed throu h said mica member and having a threaded portion for threaded connectlon with the porcelain member, the spindle including means for retaining the mica section thereon, and a wrapping of mica encompassing said spindle and positioned within the porcelain and mica members.

2. A spark-plu including a metal shell. an insulation ino uding an inner porcelain member and an outer mica member, the

' porcelain member being internally threaded,

an electrode spindlev passed through the mica section and including means at its terminal end for retaining the mica section thereon, said spindle including a threaded portion for threaded connectlon with the porcelain member to compress the mica member upon the porcelain member, and a wrapping of mica around the electrode spindle and within both the porcelain and mica members.

3. A spark-plu including a metal shell, an insulation lncIuding an inner porcelain member and an outer mica member, the porcelain member being internally threaded, an electrode spindle passed through the mica section and includin means at its terminal end for retaining t e mica section thereon, said spindle includin a threaded portion for threaded connection with the porcelain member to compress the mica member upon the porcelain member.

4. A spark-plug including a metal shell, a gland for threaded connection therewith, an insulation including a porcelain member having a flat face to be vengaged by said gland, and including a mica section, said porcelain section being internall threaded, an electrode spindle upon which the mica section is mounted and including means at its terminal end for retaining the mica section thereon, and including a threaded portion for threaded connection with the porcelain member to compress the mica section upon the said flat face of the porcelain section.

5. A:sparkplug including a metal shell, an insulation including a porcelain member anda mica member, the plug including means for exerting pressure on the lain member to retain same within the shell, said orcelain member being internally threadred, an electrode spindle including a threaded portion upon which spindle the mica section is mounted, the said threaded portion of the spindle being threaded into the porcelain member and compressing the mica member upon the porcelain member.

In testimony whereof, I aix my signature.

EDWARD H. SCHWAB.

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