Accessory gear drive for a two-cycle engine

Claim 2

A two-cycle crankcase compression engine comprising: (A) a cylinder block having a cylinder; (B) a crankcase member defining with said cylinder block a crankcase; (C) a crankshaft mounted for rotation in said crankcase; (D) a piston means mounted for reciprocation in said cylinder and coonnected to said crankshaft; (E) an intake means for admitting lubrication oil and a combustible mixture to said crankcase; (F) a worm member mounted on said crankshaft inside said crankcase, said worm member formed of a low friction plastic material and having a helical tooth; and (G) a worm gear mounted on said engine in engagement with said helical tooth.

Claim 3

The engine defined in claim 1 wherein said low friction plastic material is a plastic resin filled with a lubricating material.

Claim 4

The engine defined in claim 2 wherein said plastic resin is a nylon and said lubricating material includes molybdenum disulfide.

Claim 5

The engine defined in claim 1 wherein said worm member is a single piece and has the form of a split annular ring and further including an attachment means for attaching the ends of said worm member together.

Claim 6

The engine in claim 4 wherein one of said crankshaft and said worm member includes a circumferential flange and the other of said crankshaft and said worm member includes a circumferential groove mating with said flange to restrain said worm member from axial movement.

Claim 7

A two-cycle crankcase compression engine comprising: (A) a cylinder block including a plurality of cylinders; (B) a crankcase member defining with said cylinder block a crankcase having an upper and a lower crankcase compartment; (C) a crankshaft mounted for rotation in said crankcase, said crankshaft extending through both of said crankcase compartments; (D) pistons mounted in each of said cylinders and connected to said crankshaft; (E) an intake means for admitting lubricating oil and a combustible mixture to said crankcase compartments; (F) a seal means surrounding said crankshaft between said crankcase compartments; (G) a worm member formed of a low friction plastic material and attached to said crankshaft between said crankcase compartments above said seal means, said worm member having the form of a split ring to allow assembly on the crankshaft and having a helical tooth around its periphery; (H) a worm gear mounted on said engine in engagement with said helical tooth.

Claim 8

A two-cycle crankcase compression engine comprising: (A) a cylinder block including a plurality of cylinders; (B) a crankcase member defining with said cylinder block a crankcase having an upper and a lower crankcase compartment; (C) a crankshaft mounted for rotation in said crankcase, said crankshaft extending through both of said crankcase compartments; (D) pistons mounted in each of said cylinders and connected to said crankshaft; (E) an intake means for admitting lubricating oil and a combustible mixture to said crankcase compartments; (F) a seal means surrounding said crankshaft between said crankcase compartments; (G) a worm member formed of a low friction plastic material and attached to said crankshaft between said crankcase compartments above said seal means, said worm member having the form of a split ring to allow assembly on the crankshaft and having a helical tooth around its periphery; (H) a worm gear mounted on said engine in engagement with said helical tooth.

Claim 9

The engine defined in claim 6 wherein said worm member is a single piece and further including an attachment means for attaching the ends of said worm member together.

Claim 10

The engine defined in claim 6 wherein said low friction material is a plastic resin filled with a lubricating material.

Claim 11

The engine defined in claim 8 wherein said worm gear is formed of a metal.

Claim 12

The engine defined in claim 9 wherein said crankshaft includes a flange and said worm member includes a mating groove to restrain said worm member from axial movement.

Claim 13

A two-cycle crankcase compression engine comprising: (A) a cylinder block having a cylinder; (B) a crankcase member defining with said cylinder block a crankcase; (C) a crankshaft mounted for rotation in said crankcase and including a circumferential flange; (D) a piston means mounted for reciprocation in said cylinder and connected to said crankshaft; (E) an intake means for admitting lubrication oil and a combustible mixture to said crankcase; (F) a worm member attached to said crankshaft, said worm member formed of a low friction plastic material and having a helical tooth, said worm member having the form of a split annular ring and including a circumferential groove mating with said flange to restrain said worm member from axial movement; (G) an attachment means for attaching the ends of said worm member together; and (H) a worm gear mounted on said engine in engagement with said helical tooth.

Claim 14

A two-cycle crankcase compression engine comprising: (A) a cylinder block having a cylinder; (B) a crankcase member defining with said cylinder block a crankcase; (C) a crankshaft mounted for rotation in said crankcase and including a circumferential flange; (D) a piston means mounted for reciprocation in said cylinder and connected to said crankshaft; (E) an intake means for admitting lubrication oil and a combustible mixture to said crankcase; (F) a worm member attached to said crankshaft, said worm member formed of a low friction plastic material and having a helical tooth, said worm member having the form of a split annular ring and including a circumferential groove mating with said flange to restrain said worm member from axial movement; (G) an attachment means for attaching the ends of said worm member together; and (H) a worm gear mounted on said engine in engagement with said helical tooth.

Claim 15

The engine defined in claim 11 wherein said crankshaft includes a radial indentation and said worm member includes a radial projection engaging said indentation to prevent relative rotation between said worm member and said crankshaft.