Lawn Mower

Lawn Mowers

Two cutting mechanisms in lawn mowers are in common use:

Reel mowers, those with a set of spiral-cylindrical blades spinning on a horizontal axis. Cutting is by a scissor-like action between the moving spiral blades and a single stationary horizontal blade. The axle is attached to a gear that is then mounted on one of the wheels in order to spin the blades rapidly for good grass cutting action even when the mower is moving slowly.

Rotary mowers, those whose blades spin horizontally on a vertical driveshaft. Cutting is due to a horizontal blade striking the grass at a high speed.

The two cutting mechanisms can lead to different results. On rotary mowers, the blade is usually not sharp enough to cut the grass cleanly. The speed of the blade simply tears the grass resulting in ragged tips. By contrast, the cylinder-type reel lawn mowers and manual lawn mowers usually work by scissor action on the blades and a cleaner cut is achieved.

Lawn mowers often allow the height of the lawn mower to be adjusted to control the height of the cut grass. On older or less expensive lawn mowers, this is accomplished by manually moving each wheel to a different slot on the chassis. A more recent innovation in rotary mowers is a "one-touch" height-adjust mechanism where the blades are mounted on a frame separate from the rest of the lawn mower and the frame can be raised and lowered.

Lawn mowers need power for two purposes: to cut and to move. The act of pushing or pulling a reel mower provides power for cutting and moving at the same time. For rotary mowers, the power sources may vary: grass-cutting may be powered by either an internal combustion engine or an electric motor, while propulsion may share that power source or be supplied by the user or another external source such as a tractor. Wheel-driven gear systems allow for cutting to be powered by the same external source as that used to propel the mower.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lawn Mower"