Belt transmission

1. A belt transmission comprising:

a first belt trained between a first shaft and a first intermediate shaft;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and a second shaft;

a first tensioner and second tensioner engaged about the first intermediate shaft, the first tensioner and second tensioner each comprising a first arm and second arm and a first spring engaged therebetween, the first arm and second arm each bearing upon a housing surface, the first arm and second arm rotatable by operation of the first spring to thereby exert a force upon the first intermediate shaft to impart a tension to the first belt and second belt; and

a third tensioner and fourth tensioner engaged about the second intermediate shaft, the third tensioner and fourth tensioner each comprising a first arm and second arm and a second spring engaged therebetween, the first arm and second arm each bearing upon a housing surface, the first arm and second arm rotatable by operation of the second spring to thereby exert a force upon the second intermediate shaft to impart a tension to the second belt and third belt.

2. The belt transmission as in claim 1 , wherein the first belt comprises a multi-ribbed profile, the second belt comprises a toothed profile and the third belt comprises a toothed profile.

3. The belt transmission as in claim 1 , wherein the first spring is a torsion spring.

4. The belt transmission as in claim 1 , wherein the second spring is a torsion spring.

5. The belt transmission as in claim 1 , wherein the first shaft is an input shaft.

6. The belt transmission as in claim 1 , wherein the second shaft is an output shaft.

7. A belt transmission comprising:

a housing comprising a mount for receiving a driver;

a first belt trained between a first shaft and a first intermediate shaft;

the first shaft connectable to the driver;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and a second shaft, the second shaft connectable to a load;

a first tensioner engaged about the first intermediate shaft, the first tensioner comprising a first arm and second arm and a first spring engaged therebetween, the first arm and second arm each bearing upon a first housing surface, the first arm and second arm rotatable by operation of the first spring to exert a force upon the first intermediate shaft whereby a tension is imparted to the first belt and second belt; and

a second tensioner engaged about the second intermediate shaft, the second tensioner comprising a first arm and second arm and a second spring engaged therebetween, the first arm and second arm each bearing upon a second housing surface, the first arm and second arm rotatable by operation of the second spring to exert a force upon the second intermediate shaft, which is moveable during operation of the belt transmission, whereby a tension is imparted to the second belt and third belt.

8. The belt transmission as in claim 7 , wherein the first belt comprises a multi-ribbed profile, the second belt comprises a toothed profile and the third belt comprises a toothed profile.

9. The belt transmission as in claim 7 , wherein the first spring is a torsion spring.

10. The belt transmission as in claim 7 , wherein the second spring is a torsion spring.

11. A belt transmission comprising:

a housing comprising a mount for receiving a driver;

a first belt trained between a first shaft and a first intermediate shaft;

the first shaft connectable to the driver;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and a second shaft, the second shaft connectable to a load;

a first tensioner and a second tensioner engaged about the first intermediate shaft, the first tensioner and second tensioner each comprising a first arm and second arm and a torsion spring engaged therebetween, the first arm and second arm each bearing upon a housing surface, the first arm and second arm rotatable about the first intermediate shaft by operation of the torsion spring to exert a force upon the first intermediate shaft whereby a tension is imparted to each of the first belt and second belt; and

a third tensioner and a fourth tensioner engaged about the second intermediate shaft, the third tensioner and fourth tensioner each comprising a first arm and second arm and a torsion spring engaged therebetween, the first arm and second arm each bearing upon a second housing surface, the first arm and second arm rotatable about the second intermediate shaft by operation of the torsion spring to exert a force upon the second intermediate shaft whereby a tension is imparted to each of the second belt and third belt.

12. The belt transmission as in claim 11 , wherein the first belt comprises a multi-ribbed profile, the second belt comprises a toothed profile and the third belt comprises a toothed profile.

13. A belt transmission comprising:

a housing;

a first belt trained between a first shaft and a first intermediate shaft;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and a second shaft;

a first tensioner and second tensioner each engaged with the housing and each engaged about the first intermediate shaft whereby each tensioner exerts a force upon the first intermediate shaft which thereby imparts a tension to the first belt and to the second belt; and

a third tensioner and fourth tensioner each engaged with the housing and each engaged about the second intermediate shaft whereby each tensioner exerts a force upon the second intermediate shaft which thereby imparts a tension to the second belt and to the third belt.

14. The belt transmission as in claim 13 , wherein the first tensioner and second tensioner each comprise a first arm and second arm and a first spring engaged therebetween, the first arm and second arm each bearing upon a housing surface, the first arm and second arm moveable by operation of the first spring.

15. The belt transmission as in claim 14 , wherein the first spring comprises a torsion spring.

16. The belt transmission as in claim 13 , wherein the third tensioner and fourth tensioner each comprising a first arm and second arm and a second spring engaged therebetween, the first arm and second arm each bearing upon a housing surface, the first arm and second arm moveable by operation of the second spring.

17. The belt transmission as in claim 16 , wherein the second spring comprises a torsion spring.

18. The belt transmission as in claim 13 , wherein the first belt comprises a multi-ribbed profile, the second belt comprises a toothed profile and the third belt comprises a toothed profile.

19. A belt transmission comprising:

a housing;

a first belt trained between a first shaft and a first intermediate shaft;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and a second shaft;

a first tensioner and second tensioner each engaged with the housing and each engaged about the first intermediate shaft whereby each tensioner exerts a force upon the first intermediate shaft which thereby imparts a tension to the first belt and to the second belt; and

a third tensioner and fourth tensioner each engaged with the housing and each engaged about the second intermediate shaft whereby each tensioner exerts a force upon the second intermediate shaft which thereby imparts a tension to the second belt and to the third belt.

20. The belt transmission as in claim 19 , wherein the first tensioner comprises a first tensioner first arm and a first tensioner second arm and a first tensioner spring engaged therebetween, an arcuate first tensioner first arm surface and an arcuate first tensioner second arm surface each bearing upon a housing surface, the first tensioner first arm and first tensioner second arm moveable by operation of the first tensioner spring.

21. The belt transmission as in claim 19 , wherein the second tensioner comprises a second tensioner first arm and a second tensioner second arm and a second tensioner spring engaged therebetween, an arcuate second tensioner first arm surface and an arcuate second tensioner second arm surface each bearing upon a housing surface, the second tensioner first arm and second tensioner second arm moveable by operation of the second tensioner spring.

22. The belt transmission as in claim 19 , wherein the third tensioner comprises a third tensioner first arm and a third tensioner second arm and a third tensioner spring engaged therebetween, an arcuate third tensioner first arm surface and an arcuate third tensioner second arm surface each bearing upon a housing surface, the third tensioner first arm and third tensioner second arm moveable by operation of the third tensioner spring.

23. The belt transmission as in claim 19 , wherein the fourth tensioner comprises a fourth tensioner first arm and a fourth tensioner second arm and a fourth tensioner spring engaged therebetween, an arcuate fourth tensioner first arm surface and an arcuate fourth tensioner second arm surface each bearing upon a housing surface, the fourth tensioner first arm and fourth tensioner second arm moveable by operation of the fourth tensioner spring.

24. The belt transmission as in claim 19 , wherein the first belt comprises a multi-ribbed profile, the second belt comprises a toothed profile and the third belt comprises a toothed profile.

25. A belt transmission comprising:

a housing;

a first multi-ribbed belt trained between an input shaft and a first intermediate shaft;

a second belt having teeth trained between the first intermediate shaft and a second intermediate shaft;

a third belt having teeth trained between the second intermediate shaft and an output shaft;

a first tensioner and second tensioner each engaged with the housing and each engaged about the first intermediate shaft whereby each tensioner exerts a force upon the first intermediate shaft which thereby imparts a tension to the first belt and to the second belt; and

a third tensioner and fourth tensioner each engaged with the housing and each engaged about the second intermediate shaft whereby each tensioner exerts a force upon the second intermediate shaft which thereby imparts a tension to the second belt and to the third belt.

26. A belt transmission comprising:

an input shaft;

a first belt trained between the input shaft and a first intermediate shaft;

a second belt trained between the first intermediate shaft and a second intermediate shaft;

a third belt trained between the second intermediate shaft and an output shaft;

the position of the first intermediate shaft being moveable during operation of the belt transmission to thereby apply a tension to the first belt and second belt; and

the position of the second intermediate shaft being moveable during operation of the belt transmission to thereby apply a tension to the second belt and the third belt.

27. The belt transmission as in claim 26 , wherein the first intermediate shaft is supported by a first tensioner and a second tensioner.

28. The belt transmission as in claim 27 , wherein:

the first tensioner comprises a first arcuate surface bearing upon the housing and a second arcuate surface bearing upon the housing.

29. The belt transmission as in claim 26 , wherein the second intermediate shaft is supported by a third tensioner and a fourth tensioner.

30. The belt transmission as in claim 26 , wherein the first belt has a multi-ribbed profile.