Tension distributions during transition are governed by geometry and loading and so should be independent of manufacturing variations.

It appears that you are trying to design an automatic belt holdback/backstop since you are studying a belt clamp within,or immediately before, the transition. This is one of those devices which we hear about and even see photographed before they disappear into oblivion. There is photograph of such a device within these forums..only one.

If I'm wrong on that assumption, not unlikely, then your manual belt clamp must consider the tension in the middle bit because as your clamp presses the belt flat it all finishes up as a flat belt: assuming you have released the tension in the first place and according to Dunlop's (et al) instructions. Which, by the by, is what happens when an aforementioned backstop comes into operation although in that case the belt will also be subjected to severe whiplash near the edges due to a differential tension profile being released against a laterally diminishing burden.

The only photograph/video in captivity which I have seen shows toothed sectors hovering below and above a belt ready to bite into that belt when a freewheel or similar device activates strong springs to contact the belt. Although the device is commendably self energising the upper sector must travel down through the trough depth before it can engage the belt and of course that belt really ought to be empty to enable contact. As belt holdbacks go, they are, as yet, non-starters but not for the right reasons. ■

Originally Posted by johngateley

Tension distributions during transition are governed by geometry and loading and so should be independent of manufacturing variations.

It appears that you are trying to design an automatic belt holdback/backstop since you are studying a belt clamp within,or immediately before, the transition. This is one of those devices which we hear about and even see photographed before they disappear into oblivion. There is photograph of such a device within these forums..only one.

If I'm wrong on that assumption, not unlikely, then your manual belt clamp must consider the tension in the middle bit because as your clamp presses the belt flat it all finishes up as a flat belt: assuming you have released the tension in the first place and according to Dunlop's (et al) instructions. Which, by the by, is what happens when an aforementioned backstop comes into operation although in that case the belt will also be subjected to severe whiplash near the edges due to a differential tension profile being released against a laterally diminishing burden.

The only photograph/video in captivity which I have seen shows toothed sectors hovering below and above a belt ready to bite into that belt when a freewheel or similar device activates strong springs to contact the belt. Although the device is commendably self energising the upper sector must travel down through the trough depth before it can engage the belt and of course that belt really ought to be empty to enable contact. As belt holdbacks go, they are, as yet, non-starters but not for the right reasons.

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Dear John,

I am away on a trip at the moment. I can say we have applied the units, which is common in South African Steep Inclines/Declines. Sasol is a main user as is Anglo and others.

I will post the assembly to you, hopefully, I an navigate the new forum format. I would believe Adi Fritella, Graham Spriggs and other locals could furnish the brochures.

The unit is applied for belt breakage near the head pulley (high tension).

They have many testimonials on its efficacy. ■