US1625120A - Piston - Google Patents

Description

2 Sheets-Sheet 1 INVENTOR.

ATTORN Elbert Jfliall M1 72" E. J. HALL April 19, 1927.

PISTON Filed April 18, 1923 1,625,120 E. J. HALL PISTON April 19, 1927. v

Filed April 1a,- 192: 2 Sheets-Sheet 2 l1 i i' MI MN l "16m; 1} w 15 H in n INVENTOR. llberi Iflall '41 ATTOR EYS.

Patented Apr. 19, 1927.

um] ED STATES PATENT OFFICE.

ELBEB'J. J. HALL, OF BERKELEY, CALIFORNIA.

PISTON.

Application filed April 18, 1923. Serial No. 632,914.

This invention relates to pistons for internal combustion engines, and has for lts object to reduce piston slap and to dampen T o overcome this I providethe piston with a movable segmental portion in the side of the skirt opposite that receiving the power stroke thrust and arrange a sprlng back of this movable segmental portion to yieldingly force the same outwardly. Not only does this movable segmental portion absorb the,

slap tending to occur in a direction at right angles to the axis of the wrist pin, but, if the width of the movable portion be extended to within a short distance of the pin bosses, any tendency of the piston to' slap in a direction parallel with the axis of the wrist pin can be prevented. The action of this segmental portion can also be improved by utilizing oil to act as a check or cushion against inward movement of the said movable member.

In the accompanying drawings- Fig. 1 shows a central, vertical, sectional view of the piston embodying one form of my invention;

Fig. 2 shows a plan sectional view of the same.

Fig. 3 shows a vertical, central, sectional view of a modified form of the piston.

Fig. 4 shows a plan sectional view of the form illustrated in Fig. 3.

The piston may be of any improved design and of any desired material. In that side of the skirt opposite the side receiving the thrust on the power stroke is .a separate segmental portion 10 fitted slidabl into a recess in the skirt'of the piston. surface of this segmental portion is ground on an arc of the same diameter as the cylinder bore. Back of the segmental portion is a light coil spring 11 abutting against the wall of the piston skirt and tending to force the movable segmental portion outwardly.

In the form shown in Figs. 1 and 2 this I he outer segmental portion is provided with a chamber 12 in which the spring is seated and a duct 13 communicates with this chamber, said duct leading to the outside of the pis-, ton at a point immediately below the piston rings. Oil on the cylinder walls is thus admitted to the chamber 12 and acts as a check or cushion against inward movement of the segmental portion 10.

In Figs. 3 and 4, I show the piston cut away at oneside and a separate segmental portion 14 slidably fitted into guides 15 surrounding said cut away portion. In this form of the invention I showa bowed leaf spring 16 abutting against the opposite wall of the piston and extending, over the piston pin and pressing against the inside of the segmental portion 14.

In the operation of the piston the spring forces the movable se mental portion outwardly against the cylinder wall when the thrust is acting in the opposite direction on 1 the piston. As the iston rod passes over the center and the irection of the thrust is reversed the segmental portion will move inwardly against the spring. The effect of the heat is to weaken or lessen the resistance of the spring so that the spring may be comparatively stifi' when the piston is relatively cool and-of less resistance when the piston is hot. Thus the movable segmental portion will be held closely in contact with the cylinder wall when the piston is cool, while, at the same time, when the piston expands under higher temperatures, the spring will readily yield to allow the movable segmental portion to move inwardly."

In the form shown in Fi 1, where the oil chamber 12 is provide this chamber will become filled with oil when the segmental portion 10 moves outwardly. The oil therein will act as a check or cushion against inward movement of the segmental portion. The tendency of the piston to slap the cylinder walls will be overcome with the arrangement shown herein, and, likewise, vi-

brations occurring in the operation of the piston will be considerabl dampened. The width of the mova le segmental portionmay vary, but by widening it to withcover about one-third the circumference of the piston the slap in all directions will be prevented. I v I I prefer to make the spring 16'of thermostatic metal, that is, having an inner layer 16 of less coefficient of expansion than the outer layer 16". The effect of this is to draw the spring in, When heated, and thus lessen the outward pressure exerted by the spring upon the movable segment when the piston becomes hot. i v 7 'It is to be noted that the movable segment terminates above the bottom'of the skirt of the piston so that the entire cirrumference of the lower part of the piston skirt is left intact, thus preserving the strength of the piston,

Various changes in the. construction and arrangement of the several parts herein shown and described may be employed Without departing fromthe spirit of my invention as disclosed in the appended claim. 7

Having thus described my invention, what 1 claim and desire to secure by Letters Patcut is A piston for internal combustion engines having near its upper portion a groove for retaining a scraper ring, a movable segmental portion forming part of the piston v skirt, a chamber to contain oil arranged between the segmental portion and the wall of thepiston, and a duct leading from said chamber to the outside of the piston adja cent the scraper ring groove, whereby oil scraped by the ring will be admitted to the chamber for the purpose of forming a check against inward movement of the segmental portion.

ELBERT J. HALL.

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