chain brake

At first they were fitted with a chain brake.

The chain brake lever is usually separate, rather than being combined into the protective hand guard.

This means that the kickback is more easily controlled and the chain brake is engaged.

The chain brake has two purposes.

The chain brake was soon superseded by air operated or vacuum operated brakes.

The chain brake may be activated deliberately by the operator, or automatically by the force of a kickback event.

Chain brakes prevent movement of the saw's cutting chain by applying a steel brake band around the driven clutch drum.

For top-handled saws though, this is extremely dangerous and the clutch (and chain brake) on such a saw must always be functioning correctly.

The chain brake should also be engaged manually when not actually required, which is why top-handled saws usually have an easy brake control lever.

The chain brake is principally operated by the top-hand guard being pushed forward to engage the brake, and pulled back to disengage.

The chain brake, such as the Heberlein brake, in which a chain was connected continuously along the train.

The operation of the chain brake could be abrupt, leading to some passenger injuries, and it was replaced by a non-automatic vacuum brake by 1876.

On the recording, Dupree alternately revs the chainsaw's engine or uses the chain brake to slow the engine down to change the pitch.

Features 40:1 gas to oil mix, primer bulb for easy starting, automatic chain oiler, chain brake, anti-vibration handle and spark arrestor.

Husqvarna models also incorporate a link between the top handle and the chain brake trigger, applying the brake if the saw's bar is forced suddenly upwards.

Design was also influenced by the locomotive policies of Ramsbottom and Webb, in particular Webb's vested interests' the chain brake and radial truck.

The chain brake may also be of use when sharpening a chain on a bar, as it allows robust filing to take place without the chain slipping about.

Protection can only be successful if the chain brake has operated to stop the cutter chain as a chain running at full speed can easily cut the helmet.

A chain braking system was developed, requiring a chain to be coupled throughout the train, but it was impossible to arrange equal braking effort along the entire train.

Most chainsaw safety features are focused on the kickback problem, and seek to either avoid it (chain and bar design), or to reduce the risk of injury should it occur (chain brakes).

The pictured model has an enlarged lock-out or 'dead man' switch which, when released, also activates the chain brake, thus instantly halting the running chain as well as disengaging the throttle.

More safety features are worth their cost are a case or sheath that helps protect you from the saw's sharp teeth when you are transporting it and a chain brake that stops the chain almost instantly if necessary.

The chain brake could not be applied to stock mounted on bogies, and Moon condoned it, at a Board Meeting in 1879, as 'the most perfect brake that could be devised'- it was also the cheapest.

The BCR acquired early, in its life, several ex L.N.W.R. 4-wheel carriages, fitted with chain brakes and the illustration of one of these carriages is from the Selwyn Pearce Higgins Collection deposited at York.