What is a chainsaw used for?

Why do you need a chain brake and how is it triggered?

Chainsaws are not only used in the forest, but also increasingly in private gardens. Unfortunately, these useful devices - if used improperly - harbor a high risk potential.

Below we explain the purpose of a automatic chain brakeas well as other alternative techniques to protect the user.

You can almost imagine it: a chain brake is used to brake the chain. In truth, however, it does a lot more: the chain is stopped in a flash. The stop happens in all saws less than 0.2 seconds, and it stops not only the chain but also the motor. Electronics and motor must interact here, as stopping just one of the components - chain or motor - is not sufficient for the safety of the user.

So the chain brake does more than what happens when you simply turn off the engine: it turns on Chasingthe chain prevented.

Here we are dealing with a physical process that is easy to explain: if you look at the moving chain, you will notice that it is moving away from the user on the upper side and towards him on the lower side, i.e. from the side seen clockwise. At the point where the movement is reversed, namely at the tip of the sword, the chain moves downwards - even if only a few centimeters - and this has fatal consequences if the tip is touched on a branch or piece of wood.

Because in such a case the saw, which is exerting a force downwards at that moment, experiences after the Interaction principlea corresponding force upwards - it comes to Setbackor "kick-back", which can rip the whole saw out of your hands. If the chain continues to run at this point, it can cause extremely serious injuries to the user, and fatalities occur again and again.

Most modern chainsaws have a very pointed blade towards the front - this greatly reduces the area in which the chain runs downwards.

All chainsaws have a so-called Hand protectionor Chain brake barwhich is the central switch for the chain brake. This chain brake bar triggers the chain brake in two ways:

  • once by deliberate Press forward with the left hand,

  • second by contact with the back of the hand or glove when the saw moves upwards (like a kickback) and the user still has his hand firmly on the second handle,

  • and finally by the physical Inertia of the hand protection, an effect that is associated with the Dolmar and Makita chainsaws with "SafetyMaticBecause of its inertia, the handguard does not keep up with the saw's sword which is quickly torn upwards and folds forward - which triggers the chain brake. So even if the user in panic lets go of the left handle, this SafetyMatic- Effect, the chain will come to an immediate (less than 0.15 seconds!) Standstill.

This is related to the chain speed, among other things. If this drops below 3 meters per second, a chain brake is usually not installed and the device is supplied with a so-called. Tip protectionso that the user does not even run the risk of hitting wood with the point. The efforts of the legislator are clearly in the direction of "chain brakes for all chainsaws", so that sooner or later this will become a norm.

On the left you can see the Makita cordless chainsaw BUC122RFE.

Makita has here on the installation of an autom. Chain brake dispensed with. Instead, the sword has a tip protector on the front.

In the commercial sector, chain brakes are generally required, private users are in most cases obliged by the property owner or forest owner to use a saw with a chain brake.

All of the electric chainsaws presented by us are equipped with a chain brake, some of the cordless chainsaws are only equipped with tip protection.