Silent chain profile for linear movement
View Patent ↗The invention is a silent chain with a profile capable of corresponding with the profiles of both sprockets and racks. The purpose of the invention is to convert rotational motion to linear motion in a way that is superior to the traditional rack and pinion device by allowing for more surface area contact with the rack through the use of, rather than a pinion, a silent chain that is capable of engaging with a rack. The invented silent chain comprises link plates of a particular shape stacked in alternating rows and joined together by connecting pins in such a way as to be bendable. The link plates are shaped such that the teeth of the link plates are offset when the chain is straightened, which allows the profile of the silent chain to correspond with the profiles of both sprockets and racks.
1. A silent chain comprising:
a plurality of first link plates, each first link plate having first and second pin holes and a first and second tooth on an inner side of a line between the first and second pin holes and a third and fourth tooth on an outer side of a line between the first and second pin holes;
a plurality of second link plates, each second link plate having first and second pin holes and a first and second tooth on an inner side of a line between the first and second pin holes and a third and fourth tooth on an outer side of a line between the first and second pin holes;
wherein the silent chain is assembled by connecting first links and second links, wherein the first links are formed by stacks of m first link plates and the second links are formed by stacks of n second link plates, wherein m equals n or n plus one, and wherein the first link plates in the stacks of first link plates are interleaved with the second link plates in the stacks of second link plates, and wherein the first links and second links are connected by pins, some of which pins pass through the first pin holes of the first link plates and through the second pin holes of the second link plates, and other of which pins pass through the second pin hole of the first link plates and through the first pin holes of the second link plates;
wherein the first teeth of the first link plates and the first teeth of the second link plates have an outer edge which is angled to mate with one side of sprocket teeth and wherein the second teeth of the first link plates and the second teeth of the second link plates have an outer edge which is angled to mate with an opposite side of the sprocket teeth, when the silent chain is engaged with the sprocket teeth; and
wherein the third teeth of the first link plates and the third teeth of the second link plates have an outer edge which is angled to mate with one side of rack teeth and wherein the fourth teeth of the first link plates and the fourth teeth of the second link plates have an outer edge which is angled to mate with an opposite side of the rack teeth, when the silent chain is engaged with the rack teeth;
whereby the silent chain meshes with a sprocket and a rack simultaneously.
2. The silent chain of claim 1 , wherein a tip of each of the teeth of the first and second link plates forms an angle between about 30 and 80 degrees.
3. The silent chain of claim 1 , wherein a tip of each of the teeth of the first and second link plates forms an angle between about 55 and 60 degrees.
4. The silent chain of claim 1 , wherein each of the teeth of the first and second link plates extends from a vertical waist of each first and second link plate at an angle between about 100 and 150 degrees.
5. The silent chain of claim 1 , wherein each of the teeth of the first and second link plates extends from a vertical waist of each first and second link plate at an angle between about 125 and 130 degrees.
6. The silent chain of claim 1 , wherein a distance between central pivot points within each first pin hole and each second pin hole of each first link plate and between central pivot points within each first pin hole and each second pin hole of each second link plate measures 0.5 inches, and wherein a distance between central points of each first tooth and each second tooth and between central points of each third tooth and each fourth teeth of each first link plate and each second link plate measures between about 0.345 and 0.790 inches.
7. The silent chain of claim 1 , wherein a distance between central pivot points within each first pin hole and each second pin hole of each first link plate and between central pivot points within each first pin hole and each second pin hole of each second link plate measures 0.5 inches, and wherein a distance between central points of each first tooth and each second tooth and between central points of each third tooth and each fourth teeth of each first link plate and each second link plate measures between about 0.490 and 0.680 inches.
8. The silent chain of claim 1 , wherein a distance between central pivot points within each first pin hole and each second pin hole of each first link plate and between central pivot points within each first pin hole and each second pin hole of each second link plate measures 0.5 inches, and wherein a distance between central points of each first tooth and each second tooth and between central points of each third tooth and each fourth teeth of each first link plate and each second link plate measures between about 0.550 and 0.645 inches.
9. The silent chain of claim 1 , further comprising center guide link plates, the center guide link plates being positioned centrally within the stacks of first link plates and within the stacks of second link plates, and the center guide link plates being stadium-shaped and having no teeth.
10. The silent chain of claim 1 , wherein the pins are rocker pins.
11. The silent chain of claim 1 , wherein m equals two.
12. The silent chain of claim 1 , wherein m equals three.
13. The silent chain of claim 1 , wherein m equals four.
14. The silent chain of claim 1 , wherein m equals five.
15. The silent chain of claim 1 , wherein m equals six.
16. The silent chain of claim 1 , wherein m equals seven.
17. The silent chain of claim 1 , wherein m equals eight.
18. The silent chain of claim 1 , wherein m equals nine.
19. The silent chain of claim 1 , wherein m equals two and n equals one.