US1877774A - Internal combustion engine - Google Patents

Description

p 1932- A. MOORHOUSE INTERNAL COMBUSTION ENGINE Filed Jan. 21, 1928 jnucmfor EL RED MUUHHUUEE.

Qtfoumq Patented Sept. 20, 1932 UNITED STATES PATENT; OFFICE ALFRED MOORHOUSE, OF DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR CAB COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application mm January 21, 1928. sem -no. 248,352.

This invention relates to internal combustion engines and more particularly to pistons therefor.

Since the head of the pistonin an internal combustion engine is directly subjected to the,

high heat generated in the combustion chamber of the engine, it expands in advance of the body or skirt of the piston which is more remote, thus causing undue frictional resistance frequently resulting in the binding and chafing of the piston and the 'wall of its associated cylinder.

One of the essentials of a proper fit between a piston and acylinder of an internal combustion engine is that there shall be suflicient clearance or looseness to insure free operation when the engine is hot and yet be tight enough to minimize leakage and to pre vent what is technically known as piston slap, that is, the sudden movement of the piston from one side ofthe cylinder to the Jther, usually at the beginning of or during the explosion stroke.

An object of the invention is to provide a piston which will properly fit its associated cylinder at all operating temperatures.

Another object of the invention is to provide a piston designed to overcome piston slap and to properly fit its associated, cylinder at all operating temperatures.

Another object of the invention is to pro-' vide a piston with a divided expandible skirt portion, whereby binding and chafing of the piston in its associated cylinder is prevented.

Another object of the invention is to pro- ;vide a piston with a solid cylindrical'head vide av piston the structure of which permits of a ready replacement of the skirt portion. Yet a further object of the invention is to Aestill further object of the invention is a positive fit in its associated-cylinder, highly eflicient in operation and yet'of marked simplicity so that its manufacture is economically facilitated.

' Other objects of the invention will appear from the following description taken in connection with the drawing which forms a part of thisspecification and in which:

Figure 1 is a vertical sectional view of a piston embodying the present invention,

Figure 2 is an elevation partly broken away with one of the skirt portions removed and the other skirt portion partially removed,

Fi ure 3 is a cross sectional view taken substantlally on line 3-3 of Fig. 1, and

Figure 4 is an elevation illustrating the head of the piston with its .dependent arms in which is positioned the piston pin bosses and the hoops constituting a feature of the present invention. I

Referring to the drawing for more specific details of the invention, 10 represents, generally, a piston comprising a cylindrical head portion 11 having a plurality of piston ring grooves 12 in which are positioned piston rings 13. Formed integral with the head portion 11 in diametrically opposite positions are dependent arms or brackets 14.

to provide a piston having the advantages of These arms are set inwardly from the pe-' I riphery of the piston head as indicatedat 15, the object 0 which will hereinafter appear. The arms 14 are provided with alined bosses 16 having radial flanges 17, the bosses being bored as indicated at 18 for the rece tion of a wrist pin, not shown, and upon t e extreme lower ends of the respective arms is a bearing surface 19.

The arms 14 have cast therein reinforcing struts 20 which, as shown, are in the form of hoops. These hoops are constructed of a special alloy of steel or other suitable metal having a small coeflicient of expansion. They are cast in the arms in spaced parallel relation with respect to each other and extend transversely through the arms parallel to the face and lower edge of the piston head. These hoop portions are positioned one on each side of the piston pin bosses relatively near the top and bottom portions of the arms 14, as shown; they are provided with flat portions which are embedded in the arms 14 and thus materially strengthen the arms. These hoops are also provided with segmental or arcuate portions, the oppositely disposed edges of which are ground to provide suitable bearing surfaces for segmental skirt portions 21, and the peripheries of these arcuate portions bear upon the inner circumference of the segmental skirt portions radially when assembled in a cylinder 21 and serve to position the skirt portions.

As shown, theskirt portion of the piston comprises two semi-circular portions connected by a web 22. These skirt portions are preferably cast in pairs joined or connected by the web which is later out after the process of machining and grinding the skirt in a manner to be hereinafter described. The segmental skirt portions 21 are provided with internal flanges 23, 24 and 25. The flange 23 is ground to fit snugly beneath the lower edge of the piston head 11. The flange 24 is ground upon its upper edge to engage the lower edge of the upper hoop and the flange 25 is ground upon its lower edge to engage the upper edge of the lower loop. In other words, the flanges 24 and 25 fit between the upper and lower hoops and engage the same so as to slide freely thereon and to move therewith upon the expansion or contraction thereof. As shown, the segmental skirt portions 21 are provided with semi-circular notches 26 which register with the opening in the wrist pin bearings.

The piston head 11 and the detachable skirt portions 21 and assembled as they are placed in the cylinder which serves to maintain these elements in proper relation with respect to each other. The structure permits of expansion and contraction of the head portion of the piston independent of the divided skirt portion and the expansion and contraction of the divided skirt portion is dependent upon the expansion and contraction of the hoops positioned in the arms integral with the head portion of the piston. These hoops vary the position of the separate skirt parts radially upon varying temperatures of the piston without stress or strain or in any way impairing the strength thereof.

A piston embodying the structure 'hereln described will not stick or bind in its associated cylinder since it will not press against the wall of the cylinder with suflicient force to cause binding, nor will the piston slap since it is self-adjustable to its associated cyl nder under all temperature conditions. The skirt portions being formed of a plurality of bearing portions permit of a free expansion and contraction without friction or injurious effect to the head of the piston, the segmental portions and the associated cylinder.

It will be observed that the piston em-- braces substantially three distinct units: a head portion having integral arms in which are positioned the wrist pin bearings; supports carried by the arms and a divided skirt portion. This is a Very important factor since byvirtue of this particular structure the piston may be easily and quickly disassembled, particularly the skirt portions which may be removed without entirely extracting or removing the piston from its associated cylinder, thus affording a ready means of replacement and repair to the skirt without the necessity of entirely withdrawing the piston from the cylinderin which it is mounted, particularly the head portion thereof in which is posit oned the piston rings.

A further desirable feature to be found in this structure is that the head and skirt portions are free to expand and contract independ'ently with respect to each other and that the skirt is so supported in its relation to the head and the wrist pin bearings that the supports for the skirt serve a two-fold function in that they not only support the skirt in a highly desirable manner but they lend strength and rigidity to the wrist pin bearings. In this structure of the piston the inertia loads are low, wear and vibration are greatly reduced and the engine is made far more flex ble and responsive in its operation. While I have shown and described the preferred embodiments of my invention, I wish it to be understood that I do not confine myself to the precise details of the construction herein set forth by way of illustration as it is apparent that many changes and variations may be made therein by those skilled in the art without departing-from the spirit of the invention or exceeding the scope of the appended claims.

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

1. A piston comprising a head portion, demountable segmental skirt portions, wrist pin bearing brackets formed upon the head portion and yielding means imbedded in the brackets for positioning the demountable skirt portions radially.

2. A piston comprising a cylindrical head portion, wrist pin bearing brackets dependent from the head portion, a pair of semi-circular parts forming skirt portions, hoops carried by the dependent brackets radially positioning thesemi-circular skirt portions and means carried by the semi-circular skirt portions providing a sliding bearing surface for the hoops.

3. A piston comprising a head portion having diametrically disposed dependent brackets provided with alined wrist pin beary as til

ings, hoops embedded in the brackets above and below the bearings, a pair of semicircular parts forming skirt portions and 1means on the skirt portions overlying the oops. I 4. A piston comprising a head portion having diametrically disposed brackets pro vided with alined wrist pin bearings, hoops positioned in the brackets above and below the bearings, separate semi-circular parts forming skirt portions and means upon the semi-circular parts for axially associating the semi-circular parts with the hoops, said hoops radially positioning the semi-circular skirt arts.

5. piston comprising a head portion, dependent brackets upon the head portion set inwardly with respect to the circumference thereof and provided with wrist pin bearings, bearing surfaces formed upon the extreme ends of the brackets, hoops embedded in the brackets above and below the wrist pin bearings, a pair of semi-circular parts forming skirt portions, and flanges upon the semicircular parts adapted to extend between the hoop portions, said skirt parts having semicircular notches adapted to register with the opening in the wrist pin bearings.

6. A piston comprising in'combination a head portion having separated depending brackets, a plurality of skirt se ments surrounding said brackets, aligned earing orifices in said brackets and assembled segments, and resilient means fixed to thebrackets for exerting outward pressure on said skirt segments when the piston is assembled in ,the cylinder.

7. A piston comprising in combination a head portion, a plurality of skirt segments demountably positioned on and adjacent said head portion, aligned bearing orifices in said head portion and assembled segments, and resilient means fixedto said head portion for positioning said segments radially when the piston is assembled in a cylinder.

8. A piston comprising a cylindrical head portion, wrist pin bearing brackets formed on the head portion, hoops imbedded in the brackets, and an entirely separate slit skirt detachably associated with the'hoops and prackets and positioned radially by the oops.

9. A piston comprising a head, wrist pin brackets formed integral with and extending from the head, aplurality of free parts forming a skirt, said partshaving an inner flan e, means on the brackets associated to over is the flanges for positioning the skirt parts axially of the piston when assembled in a cylinder, and hoops fixed to the brackets and in thermal contact therewith for engaging ing from the head interiorly of the periphery, a bearing member extending outwardl from the free end of the brackets, a plura 'ty of skirtparts, means on said skirt parts adapted to engage the bottom wall of the head and the top wall of the bearings when the piston is assembled in a cylinder, and hoops inter-' mediate the bearings, and the head and carried by the brackets, said hoops bein adapted to engage the inner surface of the s irt parts toposition the same radially.

11. A piston comprising a head, wrist pin brackets extending from the head, hoops fixed to the brackets and in thermal contact therewith, and skirt sections surrounding the hoops and brackets, said skirt sections being entirely separate from the hoops and the brackets and positioned radially by the hoops and axially by the brackets when assembled in a cylinder.

In testimony whereof I aflix m si ature.

ALFRED MODE 0 SE.

the inner surface of the skirt parts adjacent the flanges to position them radially.

10. A piston comprising a head, wrist pin brackets formed integral with and entend- CERTIFICATE OF CORRECTION.

Patent No. 1,877,774 W I September 20, 1932.

ALFRED MOORHOUSE It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 422, for "and" read "are"; page 3, line 28, claim 5, for "opening" read "openings"; ard that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of March, A. D. 1933.

M. J. Moore,

(Seal) 7 Acting Commissioxzer of Patents.

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