US1283287A - Puppet-valve. - Google Patents

Description

C. A. FFANSTSEHL.

PUPPET VALVE,

APPLICATION-FILED MAR. 7. 1912.

Patented Oct. 29, 1918.

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UNITED STATES PATEN OFFICE.

CARL A. PFANSTIEHL, or HIGHLAND PARK, LLINOIs, AssIeNon 'ro PFANsTIEII COMPANY, me, or NORTH CHICAGO, ILLINoIs, A CORPORATION OF NEW YORK.

PUPPET-VALVE.

Specification of Letters Patent.

Patented Oct. 29, 1918.

Application filed March 7, 1917. Serial NO. 152,973.

To all whom it may concern:

Be it known that I, CARL A. PFANSTIEHL, a citizen of the United States, residing at Highland Park, in the county of Lake and State of Illinois, have invented a certain new and useful Improvement in Puppet- Valves, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to a puppet valve in which the head is made of tungsten or other high speed steel and in which the stem is made of steel having the expansive characteristics of 31} per cent. nickel steel.

Both tungsten and molybdenum high speed steel have very high co-efficients of expansion by reason of which valves made wholly of high speed steel have been found to be objectionable because of the great expansion of the head and stem under the excessive heat at which the exhaust valves 01' internal combustion engines are operated in practice. In order that the expansion of tungsten steel valve stems will not interfere with the proper operation of the valve after the stem has become highly heated from the exhaust gases the stems must be quite loosely fitted within the sleeves in which they reciprocate and must also be adjusted with such a wide clearance between the ends of the stems and the tappets that noise invariably results when the engine is being run under light load or under such conditions that the valve stems are not excessively heated.

The expansion of the tungsten steel valve head causes the valve to rise slightly upon its tapered seat, but this is insuflicient to compensate for the expansion of a tungsten steel stem. Tungsten steel is also a very good conductor of heat and, therefore, although the burned and burning gases only impinge upon the stem at points near the head the entire stem becomes heated to a greater extent than the surrounding iron.

Nickel may be alloyed with steel in such proportion as to substantially eliminate expansion. The United States standard measures are made of thirty-six per cent. nickel alloy steel, this alloy having a lower co-efficient of expansion than any other alloy of ordinary metals known. By lessening the proportion of nickel any degree of expansion from that of pure iron to that of thirtysix per cent. nickel can be secured.

It has been found experimentally that a stem containing substantially 311- per cent. of nickel compensates perfectly for the difference in operating temperatures between the stem and the surrounding cast iron of a water cooled engine. In order to provide a stem which will change in length between the valve seat and the end of the stem for the temperature at which the valve head and stem are operated to exactly the same amount as do the cast iron portions at the much lower temperature at which they are operated due consideration must be given to the fact that the lateral expansion of the valve head causes the head and upper end of the valve stem to rise, due to the slope of the valve seat. It will be apparent that the proportions of nickel in this alloy must be varied for different lengths of valve stems and for different facilities for carrying off the heat from the lower portions of the stem, but experiments show that two per cent. to five per cent. nickel component in the alloy will compensate for the expansion in all of the known commercial types of puppet valves.

, My invention is illustrated in the accompanying drawing upon which the head is designated as high speed steel and the stem is designated as 3 nickel steel. It is to be understood that I contemplate such proportions of nickel as will compensate for the difference in temperature between the valve and stem and its supporting parts for any valve of similar design to that illustrated in the drawing. The valve head and stem are preferably fused together by the process set forth in my application entitled puppet valves, Serial No. 138,7 80 filed December 26, 1916..

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. A valve having a tungsten steel head and a stem of substantially 3?; per cent. nickel steel.

2. A valve having a high speed steel head and a steel stem containing from 2 to 5 per cent. of nickel homogeneously attached to said head.

3. An exhaust valve for engines having a head of high speed steel and a stem of an my name this 28 day of February, A. D. alloy having a co-eificient of expansion suf- 1917. ficiently less than cast iron to compensate for the diflerence in operating temperature 5 between the valve stem and the supporting Vitnesses:

parts of the engine. MARGARET GROBBEN,

In Witness whereof I hereunto subscribe G. L. PAULLIs.

CARLA. PFANSTIEHL.

Copies of this patent may be obtained for fire centseach, by addressing the Gommissloner of Patents,

' Washington, I). O.

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