US1454762A - Piston - Google Patents

Description

May 8, 1923. 1,454,762 A. {\IELSON PISTON Filed March 7. 1921 30 agreeable noise in ay S, i923.

-NTED ADOLPH L. NELSON, F IN'DiANAPOLIS, INDIANA, ASSIGNOR OF ONE-THIRD TO S. CRAWFORD, OF INDIANAPOLIS, INDIANA.

PISTON.

Application filed March 7, 1921. Serial No. 450,189.

To all whom it nmp cdnoem:

Be it known that I, AnoLrH L. Nelson,

a citizen or the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new combustion engines. In such engines a.

great deal of heatlis evolved in the cylinders, causingboth'cyhnders and istons, to

expand. With cast iron pistons t is not excessive and-they may fit the cylinders fairly close at all times. With pistons of hi hly expan'sible metal, such as aluminum alfiiy, for example, much more clearance must be allowed, the expansion of the piston being materially greater than that of the cylinder. Some of the larger pistons are water cooled in present practice, but most a of them are not and as the top of the pis ton is subjected to very hi h temperature in use, it is necessary that t is top and adjacent parts should be materially smaller than the cylinder to avoid scoring the cy1- inders and binding of the pistons in the cyl inders. This results in excessive clearance when the engine is cool and causesaflis piston slap. a

As the engine is heated, this noise'lesse'ns and finally disappears when the clearance of the piston in the cylinder has been sufli ciently reduced. -.The object of my said invention is to pro-' vide a piston construction wherein this piston slapping noise will be eliminated; also to rovide a construction that will obviate the co eakage of oil past the c linder head and consequent objections an' alsoto prevent the loss of power resulting from loose pistons, allas will be hereinafter more fully described and claimed.

48 Referring to the accompanying drawings which are made a part hereof and on which similar reference characters indicate similar parts,

Figure -1 is a central section through'a so piston showing one form of my improved construction, I

Fi re 2, a view partly in elevation and part y in section at right angles to the section of Figure 1. I y

the cylinder, known Figure 3, a view similar to Figure 1, showing a modified'form, and

Figure 4, a similar view showing a still further modified form.

The eneral form of the piston is the same in all 516 views only differing in details as will be hereinafter more fully described.

The piston is provided with ahead 5, having grooves '6 for the packing rings, and a skirt 7. It will be understood that the normal diameter of the head 5-is slightly less than the largest-diameter of the skirt 7, providing a clearance between the head and the cylinder, to be filled or taken 7 the piston packing rings as is usual.

difierende in diameter is, however, diificult' to show on the drawings because it is so comparatively slight. As will vbe seen bycom aring Figures 1 and 2, the skirt 7 is pre er'ably of smaller diameter in thedirection of the hue of the wrist-pin than in a direction at right angles with the wrist-pin,

so that the wrist-pin bea 11 may be formed in lugs which exten both outside and inside the normal line of the wall of the skirt as indicated most clearly in Fig- .ure 2.

Said skirt 'Z- is' partially separated from thehead by slots- 8. which extend inwardly from diametrically opposite sides and parallel with the end face of the piston for adistance and then curve andextend' at right angles to said face to a oint sube s ction shown in Figures 1 and 2 it will be notedthat-these slots extend only slightly beyond the wrist-pin, while in the construction shown-in Figure-3 they extend for a.

considerable distance beyond the wrist-pin and in the construction shown in Figure 4 a less distance beyond the wrist-pin. Their length and width may be proportioned to is'to be used and the material of which the piston is made and its construction in other particulars, the purpose being 'in all cases to provide a skirt, the sides of which that are opposite the axial line 'of' the wrist-pin stantially on a line with or beyon the outer dlgf of the wrist-pin bearing. In the con-, 7 t

suit. the conditions under which the piston the contraction and expansion of the cyl- .been experienced. Said slots 8 separating the main portion of the skirt which bears against the c linder from the piston head,

serve to ins ate said skirt from said head and guard the skirt against the excessive contraction and expansion that would result if the skirt at these points was directl connected with said head. Said slots 8 thus divide the upper portions 9 of the bearing sides of the skirt from the piston head, and as the lower or extreme outer portion of the skirt is but slightly afiected by the heat from the piston head, a skirt 1s formed adapted to be substantially constant in its diameter. These portions 9 are braced by 'a bar 10 which in the form shown in Figures 1 and 2 is integral therewith and extends at right angles with the wrist-pin and above said wrist-pin connecting the upper ends of said portions 9 and holdin .them substantially rigid. Flanges an 21. may be formed around the edges of the slots 8 to stifien the parts and enable the skirt to be made of thinner metal than would otherwise be required. A web or brace 22 may also extend from one side 0 he iston head to the other, preferabl joinln'g one wrist-pin I bearing 11 with t e other and serye to stiffen and strengthen the head and also provide for transmission of heat through these reinforced metal parts as may be required to secure the degree of expansion necessary to maintain a uniform fit between the skirt and the cylinder.

In Figure 3, I show a construction similar to that shown in Figure 1, exce t that the piston head has a central depen ing lug 12 in which is secured the central portion of a cross brace 14, the ends of which are secured in lugs in the upper ends of the separated portions 9 of. the skirt. By this means the said portions are held rigid with the center of the cylinder and the piston head is kept centrallfy located in res ct to the side ortions 0 the piston, an' means is provided for transmittin the heat required to, secure the 88 81181011 necessary to maintain a uniform fit M. can the cylinder and piston.

Figure 4 shows a similar construction except the depending lug 15 and cross brace 16 are integral with the head and the separated portions 9 of the skirt.

Having thus fully described my said in-. vention, what I claim as new and desire to secure by Letters Patent is:

1. A piston for internal combustion engines comprising a head, a skirt, the skirt having slits or openings extending from immediately beneath the piston head inwardly and downwardly on each side of the wrist pin bearings to form tongues, a single brace connecting the top portions of the tongues, said tongues being unrestricted for expansion between the said upper brace and the connection of the tongue with the skirt of the piston, substantially as set forth.

2. A piston comprising a. head and a skirt formed with openings extendin transversely thereinto from opposite sides and then toward the rear of the skirt alongside the wrist-pin bearings, and a rigid brace connecting the upper ends of said separated portions, and also connected with a rigid lug centrally located on the piston head, substantially as set forth.

3. Apiston comprising a head and a skirt with wrist-pin bearings, said skirt being also formed with slots separating the head from the bearing sides of, the skirt at the upper end of said sides and an arched brace connecting said separated portions, substantially as set forth.

4. A piston comprising a circular head and a skirt with wrist-pin bearings and formed of smaller diameter in line with.

said bearings than transversely thereof and with slots separating the upper ends of the "sides of the skirt opposite the axial line-of the Wrist-pin from the head and a brace connecting said separated portions and a this 22nd day of. February, A. D. nineteen hundred and twenty-one.

ADOLPH NELSON. a 5.1

Witnesses:

E. W. Bmnronn, M. L. Summ-

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