US1757230A - Piston - Google Patents

Description

May 6, 1930. s. A. BARKER 1,757,230

PISTON Filed Jan. 5, 1930 2 Sheets-Sheet l Bnnentor Ottorypeg y 1930. v G. AiBARKER ,7

PISTON Filed Jan. s, 1950 2 Sheets-Sheet 2 3nventor (Ittorneg Patented lVlay '6, 1930 GEORGE A. BARKER, OF ROCHESTER, NEW YORK PISTON i Application filed January 3, 1930. Seria1 No.'418,386.

ennig'rnn UNDER THE ACT ormARcH s. 1883, AS AMENDED APRIL so, 1928; 370 o. e. 757) 15 Another object is to facilitate the lubrication of an engine by affording an oppor tunity for cool oil to contact the engine parts.

Still another object'is to prevent the formation of carbon deposits on the internal sur- 20 face of an engine piston.

Still anotherv object is to provide a piston construction which operates to. maintain a cooler operating temperature of that element and as a consequence avoid cracking or de-' 25. terioration of the lubricant.

A cast iron piston head in an internal combustion engine obtains a temperature in the neighborhood of 850 F. and an aluminum head about 650 F. Oil thrown upwardly by 3!) the rotation of the crank and coming in contact with this hot head has a tendency to crack and form a deposit on the lower side or in other words, on the inside of the piston. This formation'of carbon adds to the weight of one. of the most important reciprocating engine parts; As the pistons especially in expensive engines are very accurately balanced naturally the formation of carbon thereon disturbs this balanced condition.

Furthermore as carbon is a very poor conductor of heat, oil thrown into contact with the before mentioned carbon deposit fails, to a large extent to accomplish its purpose, namely to cool the piston head. So serious an obstacle does this deposit present that it is maintained by some engineers that the piston will remain cool without the oil splash system. r

In the present day engine construction oil after contacting with the hot piston has a tendency not only to break up or lose its life but also to run down the piston skirt and be deposited upon the cylinder-wall. This oil, which has obtained approximately the same temperature as the piston, on being deposited on the cylinder Walls has a tendency to thin V the lubricant alreadythereon with the re 7 suit that an oil of inferior lubricating qualities becomes the normal lubricant for the piston and cylinder. This thin condition of the oil on the cylinder'walls is further aggravated through its continual transfer between the said cylinder walls and the internal surface of the piston for as the piston descends it scrapes the lubricantfrom the cylin der walls and impels it upwardly along the internal surface of'the piston skirt and on the ascent of the 'piston this same oil having assumed the piston'temperature is returned by virtue of gravity and its owninertia to the cylinder Walls. It is obvious that the continual interchange of the lubricant between the piston and cylinder has a very deteriorating effect on the sameas well as adversely affecting the engine lubrication.

In present day engines rather elaborate rings arenecessitated to effectively prevent oilpumping which theoperatingconditions heretofore described tend to facilitate. In other wordsfthe lubricant so heated with c'on sequent lowering of its viscosity readily passes the common type of piston rings thereby entering into the combustion chamber of the engine with the consequent well understood deleterious effects.

To overcome the before mentioned operative difficulties I provide a piston with a series of ridges or projections. on. the. inside and bottom edge of its skirt. The projectionson the bottom edge'ofthe piston skirt are. so dis posed and formed that they scrape-exc'essoi'l from. the cylinder walls and deflect it into the crank caseand they also preclude lubricant coursing down the internal surface of the piston from contacting withthe cylinder walls. The projections aboveflfos'e ustvmentioned are designed to preclude lubricant on the inside ofthe piston from ascending the inside walls. thereofand contacti lg'v with the piston head and also cooperate with the said projections on the bottom of the piston skirt to aid in returning lubricant directly to the crank case. I may also employ one or more grooves in the interior faces of the piston which grooves communicate by ducts or bleeders with the interior of the piston. These grooves operate effectively to prevent oil pumping.

In order that the invention may be more readily understood reference is had to the accompanying drawings forming a part of this specification and in which- Fig. 1 is a combinationof my invention with a splash system lubricated engine; 7

Fig. 2 shows one embodiment of my piston;

Figs. 3 to 8 illustrate various modifications 1 of my piston construction.

An engine piston broadly designated as (l) is provided on its interior surface with a series of annular projections (2) having a lower side (2 normal to the piston walls and an upper side (2 at an angle thereto. Further projections (3) and.( l) are provided on the base of its skirt. Peripherial grooves (5) are fashioned in thelower part of the exterior face of the piston and communicate through ducts or bleeders-( 6) with the inside of the piston. The construction is such that oil descending the interior surfaces of the piston is precludedthrough. the intermediary of the projections (2) and (3) from engaging with the cylinder walls-while surplus oil already deposited on the latter walls is removed by projection. (4) upon the descent of the piston and deflected into the crank case by projection (3). Projections (2) through their specific construction prevent the upward movement of lubricant along the inside of the piston but facilitate clownward passage-thereof. Tl1eseprojections.(2) also'operate toproject the lubricant back into the crank casewithout permitting. allofit to v traverse the piston on thelubricants down- Ward passage. Assisting projection. (4;) on the descent ofthe piston and similarly functioning to remove surplus oil on the ascent of the piston are grooves (5) which through the ducts,(6) convey the oil they collect to the interior of the piston from which point it is immediately returned to the crank caseby virtue v of projections (2) and (3). These grooves (5) are fashioned with lips (5 and (5 to facilitate .the removal of; the said surplus lubricantonboth the pistons ascent anddescent, H

.It is obvious with this constructionflthe time during which aparticular quantity of lubricantis on the pistons and cylinder walls is ajminimum with the result that cool oil from they crank case is better able toassum'e,

the burden of-loweringthetemperature of and lubricatingthe engine vparts. With such a condition obtaining the formation. of carbon deposits is inhibited as isalsooil pump ing and the lubricatingquality of the oil is not quickly impaired; Furthermore the projections on the piston operate to radiate heat therefrom and cooperate with the splash system to cool the cylinder and piston.

Having described my invention, what I claim as new and wish to secure by Letters Patent is:

1 1. In a cylinder, a piston having annular projections on its interior, each projection embodying a normal side and an angular side whereby lubricant deposited on the projections is precludedfrom-ascending the internal surface of the piston...

2. In a piston having annular grooves on its exterior, ducts communicating the grooves and inside of the piston, projections on the piston interior adjacent the ducts, each of said projections having a normal side and an angular side whereby lubricant from the grooves and ducts is precluded from ascending the internal surface of the piston. A piston having a groove on its exterior, said groove fashioned with'upper and lower lips, annular projections on the inside of the piston and a duct communicating the groove with a point inside of the piston adjacent the projections. p

4. A piston having a double lipped groove on its exterior, projections on its interior each having a normal and an angular side and a duct communicating the groove with a point inside of the piston adjacent the projections for the purpose described. p

5. In a lubricatedpiston and cylinder, a piston having a double lipped groove on its exterior, a duct communicating the groove and piston interior and projections on the piston interior to preclude lubricant from the duct from ascending the inside wall of the piston. j

6. In a lubricated piston and cylinder, a

piston having a double lipped groove on its exterior, a duct communicating the groove and piston interior. andpro ectlons on the piston interiorto preclude, lubricant from 1

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