US1755710A - Internal-combustion-engine piston - Google Patents

Description

April 22, 1930. H, A, sbu s ET-AL 1,755,710

INTERNAL COMBUSTION ENGINE PISTON Filed June 50, 1927 I I /5' INVENTO\R Z3 Patented Apr. '22, 1930 UNITED STATES PATENT OFFICE mom) A. SOULIS Ann WTLBUR '1'. soULis, on EAS'ION, PENNSYLVANIA lNTERNALCOMBUSTION-ENGINE PISTON Application filed June 80,

The invention is an improvement in pistons for internal combustion engines and means tor constructlng the same whereby the efliciency of internal combustion engines in 1 5 which our invention is embodied will be materially increased.

As is well known, pistons constructed of all iron are strong and have good wearing qualities. However, cast iron pistons are heavy and their thermal conductivity is low; therefore the compression ratio must be held down and the speed of the engine limited. As the tendency in modern engine design is to raise the compression ratio and increase the engine speed, the iron piston hinders the advancement of engine design. The aluminum piston has high thermal conductivity and is light in'weight, but due to the inherently poor wearing qualities of aluminum the piston is short lived. The aluminum piston also has a high ratio of expansion which does not permit the piston to be fitted in the cylinder to limits close enough to prevent piston slap and oil pumping and loss of compression. It is seen that a piston to have ideal wearing and thermal properties and to be light in weight must be constructed of more than one metal. Therefore a bi-metallic piston of a substantial construction will be light in weight and have high thermal conductivity. It will therefore have all of the advantages and none of the disadvantages of a piston of cast iron or of aluminum.

35 An object of our invention is to so construct a piston of two unlike metals that they will be permanently united in a, manner to securely lock the two metals together so as to keep the uniting joint together at all times so as to function like a piston constructed of a single casting.

A further object of our invention is to provide a piston for use in an internal combustion engine, which will fulfill the exacting requirements hereinbefore specified, and this in a device which is simple in construction, reliable in operation, light in weight, low skirt expansion and with long life.

Other objects and advantages flowing from 30 the utilizatlon of our invention will doubtless the wrist pin hole.

1927. Serial No. 202,623.

present themselves as the description proceeds and we would have it clearly understood that we reserve for ourselves all rights to the full range of equivalents, both in manner-of practicing .our method or process and its use, to which we may be entitled under our invention in its broadest aspect.

For a consideration of what we. believe to be novel in our invention, attention is directed to the accompanying description and claims appended thereto.

We shall now proceed to describe our invention with reference to the accompanying drawings, wherein we have illustrated certain preferred embodiments for the purpose of presenting a clear and comprehensive disclosure, it being obvious that our invention is susceptible of taking other forms without departing from the scope and spirit thereof.

Fig. 1 is a plan in section, taken through D-D of Fig. 2 showing the head metal boss extension extending down into the locking space provided in the shell section.

Fig. 2 is an elevation, in section, taken through EE of Fig. 1, showing the inset lock section of the piston shell attached to the piston head section.

Fig. 3 is an elevation, in section, taken through FF of Fig. 4, showing the head 0 nilletlal extending down to lock into the piston s e l.

Fig. 4 is a plan of Fig. 3 looking toward the piston head.

Fig. 5 is an elevation showing the general arrangement of the piston with its shell section slotted.

Fig. 6 is an elevation showing the general arrangement of the piston, looking toward Fig. 7 is an elevation showing the piston shell with its inset locking section.

Fig.8 is a plan of Fig. 7.

Fig. 9 is an elevation, in section, showing the piston shell with a turned in reinforcing ledge at the end of which the inset locking wall is located.

Referring now to the drawings in detail in which like characters of reference are employed to designate similar parts throughout the several views, 9 indicates a piston shell constructed of some metal such as a ferrous metal or other metal having like characteristics.

At 10 is shown the shell inset lock sections with lock holes 11 through which the head metal flows to lock the head section and shell sections together. At 12 is shown the head metal extension with wrist pin boss 13. At 14 is shown the wrist pin boss rib which may be single or of any number found necessary for each design. At 15 is shown a ledge which may or may not be in the piston con struction, as the individual design warrants. At 16 is a slot to allow the shell to be flexible and is used where the cylinder has not received accurate finishing. At 17 is shown a piston shell. At 22 is a reinforcing ledge adjacent the end of the shell having inset locking surfaces 23 with lock holes 24.

It is seen that in some instancesit may be desirable to modify the number or shape of the locking holes and that the wrist pin boss recess may be modified to meet a 'diflI'erent condition of construction.

We claim:

1. A piston having a shell ofcast' iron with I a thin wall having diametrically opposed recesses therein extending downwardly from its upper edge and a horizontally disposed integral inwardly projectin surface adjacent the base of each of sai recesses and a "head of a lighter metal cast on said shell to said surfaces, said depending portions providing wrist-pin bearings.

2. A piston having a shell of cast iron formed with a thin wall having diametrically opposed recesses therein extending downwardly from its upperv edge and a horizontally disposed integral inwardly projecting ledge adjacent the base of each of said recesses, each of said ledges having openings therein disposed on either side of the central portion thereof and a head of an aluminum alloy cast on said shell with dependent per-- tions embracing said ledges, said alloy being disposed within said openings, the aforesaid dependent portions being adapted to form wrist-pin bearings.

3. A bi-metallic piston having a cylindrical shell of cast iron, diametrically opposite portions of the wall being inset to form an integral horizontally disposed inwardly projecting ledge merging into a vertical upwardly directed surface, the latter surface being provided with a wrist pin opening and a head of aluminum alloy cast upon said shell, said head having dependent portions completely surrounding the horizontal ledgeand the integral vertical surfaces, said dependent portions forming wrist pin bosses, and a diametrically disposed reinforcing rib integral with the inner surface of said head head having wrist in bosses formed integral therewith and em racing the vertical and horizontal surfaces of said inset portion of the wall, the alloy in contact with the inner and outer faces of each of said surfaces being connected through the a ertures therein.

HARO D A. SOULIS. WILBUR T. SOULIS.

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