Short pitch tooth chain

Abstract

A short pitch tooth chain that reduces the level of impact noise generated during operation is disclosed. A chain system includes a first sprocket having a plurality of sprocket teeth spaced apart by a first distance, a second sprocket also having a plurality of sprocket teeth spaced apart by the first distance, and a short pitch tooth chain wrapped around the first and second sprockets. The short pitch tooth chain includes a first link having a first aperture spaced from a second aperture by a second distance, a second link having a first toe spaced from a second toe by the first distance, the second link having a third aperture and being connected to the first link by a first pin extending through the first and third apertures, and a third link having a third toe spaced from a fourth toe by the first distance, the third link having a fourth aperture and being connected to the first link by a second pin extending through the second and fourth apertures. The first distance defines a sprocket chordal pitch and the second distance defines a chain pitch wherein the chain pitch is about twice the sprocket chordal pitch.

Description

CROSS REFERENCE TO RELATED APPLICATIONS1. This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60 / 074,252, filed Feb. 10, 1998.BACKGROUND OF THE INVENTION2. The present invention relates to the chain arts, and in particular, a short pitch tooth chain that provides improved noise reduction over conventional tooth chains.3. Drive chain systems and timing chain systems incorporating known chains such as inverted tooth chains and roller chains have several components of undesirable noise. A major source of noise is the sound generated as the chain engaging members, such as inverted teeth or rollers, leave the span and collide with a sprocket during meshing. The resulting impact noise is repeated with a frequency generally equal to that of the frequency of the chain meshing with the sprocket. It is known that the impact noise levels associated with chains can be reduced by altering the engagement geometry of the chain and / or sprocket to, in part, reduce the...

AI Technical Summary

Benefits of technology

10. One advantage of the present invention is the provision of a short pitch tooth chain which reduces noise levels by increasing the frequency at which the chain meshes with a sprocket to a level which is inaudible, or at least less audible to the human ear.

is the provision of a short pitch tooth chain which reduces noise levels by increasing the frequency at which the chain meshes with a sprocket to a level which is inaudible, or at least less audible to the human ear.

11. Another advantage of the present invention is the provision of a short pitch tooth chain having a chain pitch value which is approximately twice a sprocket chordal pitch value.

12. A further advantage of the present invention is the provision of a chain system having a short pitch tooth chain that reduces noise levels by increasing the frequency at which the chain meshes with a sprocket to a level which is inaudible, or at least less audible to the human ear.

13. Yet another advantage of the present invention is the provision of chain system having a short pitch tooth chain with a chain pitch value which is approximately twice a sprocket chordal pitch value.

Problems solved by technology

3. Drive chain systems and timing chain systems incorporating known chains such as inverted tooth chains and roller chains have several components of undesirable noise.

A major source of noise is the sound generated as the chain engaging members, such as inverted teeth or rollers, leave the span and collide with a sprocket during meshing.

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