Two-stroke engine piston stuffer

Claim 2

A one-piece piston stuffer for disposition in the lower end of a two-stroke cycle internal combustion engine cylinder bore, said stuffer including base means adapted to be seated in the upwardly opening portion of the crankcase of said engine over which a cylinder barrel is supported with first portions of the base means overlying upwardly facing surface portions of said crankcase disposed outwardly of the cylinder bore and second portions of said base means underlying downwardly facing surface portions disposed outwardly of said bore for clamping in position between said upward and downwardly facing surfaces when said barrel is mounted over said upwardly opening portion of said crankcase, said stuffer including a pair of upstanding opposite side standard portions adapted to project upwardly into the lower end of said barrel, said standard portions being generally inverted U-shaped in configuration and lying in generally parallel upright planes extending along opposite sides of said stuffer, said U-shaped standard portions each including upstanding legs interconnected at their upper ends by means of a bight portion extending therebetween, said stuffer being free of portions extending between the lower ends of corresponding legs of its standard portions inwardly of the surfaces of the lower ends of each pair of corresponding legs facing the other pair of corresponding legs of said standard portions.

Claim 3

The combination of claim 1 wherein the opposing surfaces of said bight portions are downwardly and outwardly beveled.

Claim 4

The combination of claim 1 wherein said stuffer includes opposite end outwardly projecting wings extending between said opposite side standard portions, said wings including lower surfaces defining said first portions.

Claim 5

The combination of claim 3 whereIn said stuffer includes opposite side outwardly projecting feet, said feet including upper surfaces defining said second portions.

Claim 6

The combination of claim 4 wherein said stuffer includes opposite end outwardly projecting wings extending between said opposite side standard portions, said wings including lower surfaces defining said first portions.

Claim 7

The combination of claim 3 wherein said stuffer includes opposite side outwardly projecting feet, said feet including upper surfaces defining said second portions, said feet equaling four in number and being carried by the lower ends of said legs.

Claim 8

The combination of claim 1 wherein the lower ends of corresponding legs of said standard portions are interconnected by opposite end generally C-shaped and horizontally disposed wings opening inwardly toward the center of said stuffer, said first second portions being defined by upper and lower surfaces of said wings.

Claim 9

The combination of claim 1 wherein said stuffer includes opposite side outwardly projecting feet, said feet including upper and lower surfaces defining said second and first portions, respectively.

Claim 10

The combination of claim 8 wherein said feet include arcuate outer peripheral edges whose centers of curvature coincide with each other and the vertical center axis of said stuffer.

Claim 11

The combination of claim 9 wherein said outer peripheral edges of said feet include circumferentially spaced outwardly and upwardly opening notches formed therein adapted to be registered with corresponding notches formed in said crankcase for the utilization of downwardly insertable key members in said registered notches to prevent rotation of said stuffer about said vertical center axis relative to said crankcase.

Claim 12

In combination, a two-stroke cycle internal combustion engine of the type including a crankcase having a cylinder barrel mounting surface thereon through which an opening is formed and upon which the inner end of a cylinder barrel is removably seated, said engine further including upwardly facing stepped crankcase surfaces disposed within said opening below said mounting surface, a piston stuffer comprising a body defining upstanding opposite side body members interconnected at their corresponding lower ends by body portions extending therebetween and projecting endwise outwardly in opposite directions from the opposite ends of said body members, said stuffer being disposed within the lower end of said barrel and said body portions including stepped undersurfaces mating with and seated downwardly upon said upwardly facing stepped crankcase surfaces, said engine including a piston reciprocal in said barrel, a crankshaft journaled in said crankcase and a connecting rod connecting said piston to said crankshaft, the upper portions of said upstanding opposite side body members being contoured to be free of contact with said connecting rod during rotation of said crankshaft and receivable upwardly into the lower end of said piston independent of contact therewith upon downward movement of said piston in said barrel to its lowermost limit position therein, and pairs of aligned bores formed through said body portions and in said crankcase, said bores in said crankcase being threaded, and threaded elongated fasteners secured through said body portions and in said threaded bores.

Claim 13

In combination, a two-stroke cycle internal combustion engine of the type including a crankcase having a cylinder barrel mounting surface thereon through which an opening is formed and upon which the inner end of a cylinder barrel is removably seated, said engine further including upwardly facing stepped crankcase surfaces disposed within said opening below said mounting surface, a piston stuffer comprising a body defining upstanding opposite side body members interconnected at their corresponding lower ends by body portions extending therebetween and projecting endwise outwardly in opposite directions from the opposite ends of said body members, said stuffer being disposed within the lower end of said barrel and said body portions including stepped undersurfaces mating with and seated downwardly upon said upwardly facing stepped crankcase surfaces, said engine including a piston reciprocal in said barrel, a crankshaft journaled in said crankcase and a connecting rod connecting said piston to said crankshaft, the upper portions of said upstanding opposite side body members being contoured to be free of contact with said connecting rod during rotation of said crankshaft and receivable upwardly into the lower end of said piston independent of contact therewith upon downward movement of said piston in said barrel to its lowermost limit position therein, and pairs of aligned bores formed through said body portions and in said crankcase, said bores in said crankcase being threaded, and threaded elongated fasteners secured through said body portions and in said threaded bores.

Claim 14

The combination of claim 11 wherein said side body members comprise U-shaped standard portions each including upstanding legs interconnected at their upper ends by means of a bight portion extending therebetween, the opposing surfaces of said bight portions being downwardly and outwardly beveled.

Claim 15

The combination of claim 12 wherein said bores are downwardly and outwardly inclined bores and said crankcase bores comprise through oil passages, said fastener having axial bores formed therethrough.