kickback guard

[glens]

Does it work like Stihl's more elegant mechanism such that you hold it down, or does your hand go under (or through?) it?

Glen

 

[Lobo]

Does it work like Stihl's more elegant mechanism such that you hold it down, or does your hand go under (or through?) it?

Glen

Glen do you have pic's or a link to Stihl's device?

 

[glens]

It's only available on a few models.

http://www.stihlusa.com/chainsaws/MS360QS.html
http://www.stihlusa.com/chainsaws/chain_brake.html

 

[Molecule]

mange -- that thing is pretty nice ... how does it work ... does your right hand go under it (basic question for starters) ? when the saw rocks back around its center of gravity, does the wrist of your right hand then push the lever upward, which then pulls a wire attached to some kind of ratchet on the end of the chain brake band which is usually fixed to the chasis or side plate (the other "free" end of the chain brake band being attached to the spring loaded trigger system which is activated by the front handle guard) so that when your wrist pulls up on the lever, it tightens that end of the brake band?

If you could possibly take a picture, or even sketch a small diagram, of it with your hand in it, chain brake not activated, and a picture/diagram with your hand in it, with chain brake activated as in kickback, I for one would be most appreciative.

it's always amazes me how much more is continually being invented on the chainsaw ...

in any case, thanks for the pictures so far.

 

[Mange]

mange -- that thing is pretty nice ... how does it work ... does your right hand go under it (basic question for starters) ? when the saw rocks back around its center of gravity, does the wrist of your right hand then push the lever upward, which then pulls a wire attached to some kind of ratchet on the end of the chain brake band which is usually fixed to the chasis or side plate (the other "free" end of the chain brake band being attached to the spring loaded trigger system which is activated by the front handle guard) so that when your wrist pulls up on the lever, it tightens that end of the brake band?

If you could possibly take a picture, or even sketch a small diagram, of it with your hand in it, chain brake not activated, and a picture/diagram with your hand in it, with chain brake activated as in kickback, I for one would be most appreciative.

it's always amazes me how much more is continually being invented on the chainsaw ...

in any case, thanks for the pictures so far.

Yes, that is correct.
I will see what I can do about a pic.

 

[chainsawworld]

some time ago i saw an idea for an anti-kick back device. it was a hook that bolted to the bumper spike. the idea was that the hook would swing under the saw during cutting. when kick-back took place the hook would swing up and catch the log keeping the saw down away from the cutter. i doubt it.
here is a crude drawing of the crude device. marty

 

[Lobo]

Here you go.

This is a good thing.

Mange is it connected to the brake band itself ?

 

[Mange]

Yes, it it two triggers on the same gun barrel, so to speak.
Each trigger is independent, but have the same result.

 

[Molecule]

mange -- the thing that I was trying to figure out was the ratchet system ... thus when the cable from the wrist assembly pulls on the back end of the chainbrake band, there would have to be some kind of ratchet or something to prevent that back end (formerly fixed to the saw frame) from just sliding around. If "back-motion" wasn't somehow prevented, by a ratchet system of somekind, it would effectively negate the effect of the spring on the front end of the chainbrake band. So a ratchet migth be design option (a). design option (b) might be to have the cable from the wrist lever activate the trigger mechanism on the front spring (just like front hand lever does, somehow), and leave the back end of the brake band fixed to the chasis as before. under this option (b), when the wrist lever comes up, the cable would "trip" the trigger holding back the compressed spring, and the spring then tightens the front-end of the brake band, the back end being still fixed. Maybe there is an option (c) ?

I like that design ... it's ridiculuous if the utility of a personal safety device like this can be trumped by fear and greed ... Husky should get a patent for their creativeness and for their investment in prototypes etc, and they should be a return on that, but they should also be required to share safety technology with other manufacturers at a reasonable price.

 

[Lobo]

It's only available on a few models.

http://www.stihlusa.com/chainsaws/MS360QS.html
http://www.stihlusa.com/chainsaws/chain_brake.html

Glen may be I don't understand the QS system correctly, but having to remove your hand off it completely before it engages or stops the chain to me can be a little late and the damage can have already happened. (stops the chain in one second)

What am I missing here ?

 

[glens]

Mange hadn't yet clarified whether that contraption was gripped or not when I posted that.

I haven't used a QS-equipped saw, so I don't know how completely the handle needs to be gripped to release the brake.  It may not function as well as a kickback-stopper as what Mange showed us.

Glen

 

[Mange]

mange -- the thing that I was trying to figure out was the ratchet system ... thus when the cable from the wrist assembly pulls on the back end of the chainbrake band, there would have to be some kind of ratchet or something to prevent that back end (formerly fixed to the saw frame) from just sliding around. If "back-motion" wasn't somehow prevented, by a ratchet system of somekind, it would effectively negate the effect of the spring on the front end of the chainbrake band. So a ratchet migth be design option (a). design option (b) might be to have the cable from the wrist lever activate the trigger mechanism on the front spring (just like front hand lever does, somehow), and leave the back end of the brake band fixed to the chasis as before. under this option (b), when the wrist lever comes up, the cable would "trip" the trigger holding back the compressed spring, and the spring then tightens the front-end of the brake band, the back end being still fixed. Maybe there is an option (c) ?

I like that design ... it's ridiculuous if the utility of a personal safety device like this can be trumped by fear and greed ... Husky should get a patent for their creativeness and for their investment in prototypes etc, and they should be a return on that, but they should also be required to share safety technology with other manufacturers at a reasonable price.

The mekanism is the same as a regular brake. It is the cable and the device it self that is different. This is simply added to an regular brake.
I am not sure what to say.
This is a simple design, that use a existing funktion. It even use existing holes for assembly.

 

[Lobo]

I haven't used a QS-equipped saw, so I don't know how completely the handle needs to be gripped to release the brake.  It may not function as well as a kickback-stopper as what Mange showed us.

Glen

My initial impression is that the husky system Mange has shown us is probably quicker to respond than the Stihl system. Once again I have not tried the Stihl QS system either.

 

[WRW]

My initial impression is that the husky system Mange has shown us is probably quicker to respond than the Stihl system. Once again I have not tried the Stihl QS system either.

Looking at the Stihl system, it appears to be more for stopping the chain between cuts than as a redundant system for kickback.

 

[Lobo]

Looking at the Stihl system, it appears to be more for stopping the chain between cuts than as a redundant system for kickback.

Makes sense to me !

 

[Mange]

This system react very fast, a flick of the wrist I have no 242 to mount this on, but I will see what i can do.