DE2435106A1 - Motor-mower device saving energy and increasing performance - rotational axis of cutter-blades angled at less than right angle - Google Patents

Abstract

A mower usually has blades rotating parallel to the ground's surface. The energy lost through friction on the grass already cut, by grass collecting in the centre of rotation, and by stalks being cut through several times, can be conserved by altering the angle of the blades from the usual one of right angles to the ground. If the blades are positioned at an angle of less than ninety degrees to the ground, only the outer ends touch the grass in the front cutting semi-circle and the friction with the already mown grass is reduced to a minimum. The desired slanting angle of the cutter blades can be produced by, for example, a pair of wheels with different diameter.

Description

Process for saving energy and increasing the performance of motorized lawnmowers Lawn mowers with blades rotating parallel to the ground surface have a bad effect Efficiency. Much of the energy expended is due to friction on the lawns that have already been cut, furthermore by balling up grass in the rotation center and consumed by cutting through blades of grass several times.

Studies have shown that the efficiency and thus the Can increase performance by more than 100% if the rotation axis of the knife is not at right angles to the floor surface, but at an angle smaller in the direction of travel inclined than 9o degrees.

With this arrangement, only the outer ends of the knives are in the front half of the cutting circle in the area of a narrow ring area with the lawn in Touch The friction between the knife and the already cut grass that acts as a brush is reduced to a minimum. If you examine a normal lawn, so you can see that it is not a smooth, even surface, but a hump and having depressions at short intervals.

If a pair of wheels of the lawn mower drives into depressions, the knife abruptly lowered towards the floor surface. In the case of a parallel knife, this is called that the already cut grass is under the full knife cutting circle area initially acts as a brake until it is cut off a second time. Come in addition, that the knives usually only have knife edges at their outer ends. In to the The grass is chopped off and used in the area in which the knives do not have any cutting edges The axis of rotation is only turned over and clumped together and partially crushed. The energy required for this is considerable.

With the saving of energy with the inclined knife further advantages connected. Since you can use smaller gasoline engines, reduced noise and pollution from combustion gases. Further cordless lawnmowers can be used on a larger scale for densely populated Residential areas because of their quiet running and their operation without generating combustion products are of particular importance.

Another advantage is seen in the fact that the user of the Mower is more or less encouraged to push the mower and not pulling towards you, which is expected to reduce foot injury accidents will.

The inclined knife axis position provided by this procedure can be achieved by various known devices or components, for example, through pairs of impellers with different diameters. Latter can also be retrofitted to existing mowers without major costs attach.

Claims (1)

Claim: Process for saving energy and increasing the performance of motorized lawnmowers with rotating knives characterized in that the knife axis of rotation is related on the lawn surface in the direction of travel of the mower at an angle smaller is arranged as 90 degrees.