The present invention is concerned with the field of mechanized garden cultivation and its object is a scarifier, moss rake and lawn or grass aerator device.
Various small devices are known which are intended mainly for lawn maintenance and which carry tools in the form of blades rotating in a vertical plane and disposed along a motor driven shaft. A first type of device comprises a frame in the form of a box open at its bottom face and supporting a motor on its top face, which forms a cover; one or more shafts supporting the blades is or are disposed inside the box; this shaft is in turn supported by bearings on the box and is driven by the motor with the aid of a chain drive, for example; the box is provided with side wheels or rollers. In a device of this kind the depth of cut is adjustable by regulating either the height of the shaft relative to the wheels or the height of the wheels relative to the box. Devices of this kind are practical, but they have the disadvantage of being dedicated to one particular type of work.
Small devices of the motorized rake type are also known, in which the drive half-shafts project at the side of a motor casing and are adapted to receive either wheels, when the device is to be used as traction means, or rotary tools. To enable the device to be used as a scarifier, equipments have thus been proposed which consist of a pair of shafts adapted to be connected by sleeve couplings to the drive half-shafts at one end, while their other end is provided with a wheel hub and a wheel adapted to turn freely about the hub; each shaft carries a plurality of scarifier blades; the coupled end is fastened to the drive half-shaft by means of a pin; the rotation of the motor rotates the blades, while the rotation of the wheels, that is to say the propulsion of the device, is dependent solely on the operator. The advantage of a device of this kind is its ability to be used for various types of work, but a disadvantage is that the depth of cut into the ground is dependent on the diameter of the wheels, and is therefore not adjustable for a given equipment.
For more precise information regarding the prior art reference may be made to the following publications: U.S.-A-No. 4,483,400 (ARNDT), U.S.-A-No. 3,127,940 (HUTCHINSON), U.S.-A-No. 2,794,308 (CAVANAUG), FR-A-1,376,521 (BRIBAN) and FR-A-690,298 (KOROUM).